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Regulators ICs for Digital Cameras and Camcorders
Switching Regulator IC
with Built-in FET (5V)
BD9757MWV
●Description
BD9757MWV is an 8-channel switching regulator with a built-in FET for digital still camera. It has a built-in function to
light-control the white LED for backlight accordin g to the li ght control setting signal from microcomputer.
●Features
1) Starting from VBAT terminal of 1.5V
2) Power of internal circuit is supplied from voltage boost CH1
3) Mounted with a total of 8ch including voltage boost 2ch, voltage step-do wn 4ch, inversion 1ch, and white
LED-purpose voltage boost (compatible with DC light control) 1ch
4) Built-in 5-channel transistors for synchronous rectification
5) Built-in 2-channel FET transistors for voltage boost
6) Built-in all-channel phase compensation between input and output of error amplifier
7) Channel 1 and 3 are common, but other channels are independent, so the ON/OF F is possible
8) Operating frequencies of 1.2MHz (CH1 ~ 5), 600KHz(CH 6 ~ 8)
9) Built-in output breaking circuit (timer latch type) at the time of overload
10) Built-in 2ch of high side switch with soft start function
11) UQFN044V6060 package (6mm×6mm ,0.4mm pitch) with heat dissipation
●Applications
Digital still camera
●Absolute maximum ratings (Ta=25℃)
Parameter Symbol Ratings Units
Power Supply Voltage VBAT -0.3 ~ 7 V
Power Input Voltage
VHx1 ~ 5 -0.3 ~ 7 V
HS78H -0.3 ~ 7 V
VLx7,8 -0.3 ~ 22 V
Maximum output current
IomaxLx1 ±2.5 A
IomaxHx1 ±1.5 A
IomaxHx2,5 +1.0 A
IomaxHx3,4 +0.8 A
IomaxHS78 +1.2 A
IomaxLx7,8 ±1.0 A
Power Dissipation Pd 0.54(※1) W
Operating temperature range Topr -25 ~ +85 ℃
Storage temperature range Tstg -55 ~ +150 ℃
Junction temperature Tjmax +150 ℃
※1 At the time of a single IC. If used in more than Ta=25℃, reduced by 4.32mW/℃.
No.10036EAT09
Technical Note
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BD9757MWV
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●Operating conditions
Parameter Symbol Ratings Unit conditions
Min. Typ. Max.
Power supply voltage VBAT 1.5 - 5.5 V
VREF terminal connection capacity CVREF 0.47 1.0 4.7 μF
VREGA terminal connection capacity CVREGA 0.47 1.0 4.7 μF
【CH8 modulated light】
H fixed time when the modulated
light control setting is determined TON 265X
1/fosc1 - - sec
L fixed time when OFF TOFF 256X
1/fosc1 - - sec
H fixed time at the time of
modulated light control setting TH 500 - 10000 nsec
L fixed time at the time of
modulated light control setting TL 500 - 10000 nsec
H fixed time at the time of EN starting up TEN 4X
1/fosc1 - - sec
L fixed time
before modulated light control setting TCLR 7X
1/fosc1 - 255X
1/fosc1 sec
Time of light control setting
at the time of starting up TSET - -
2048X
1/fosc1 sec
【Driver】
CH1 PMOS drain current Idpl1 - - 1.2 A
CH1 NMOS drain current Idnl1 - - 2.3 A
CH2,5 PMOS drain current Idpl2 - - 0.8 A
CH2, 5 NMOS drain current Idnl2 - - 0.8 A
CH3, 4 PMOS drain current Idpl22 - - 0.6 A
CH3, 4 NMOS drain current Idnl22 - - 0.6 A
CH6 driver output peak curre nt Idpeak - - ±0.5 A
CH7, 8 high side switch input current Idpl7,8 - - 1.0 A
CH7, 8 NMOS drain current Idnl6 - - 0.8 A
【Output voltage setting range】
CH1 - 4.5 - 5.4 V
CH2 - 1.0 - 4.4 V
CH3 - 1.0 - 4.4 V
CH4 - 1.0 - 4.4 V
CH5 - 1.0 - 4.4 V
CH6 - -8.0 - -5.0 V
CH7 - 8.5 - 16 V
CH8 - 8.5 - 20 V
Technical Note
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●Electrical cha r acteristics (Unless specified, Ta=25℃, VCCOUT=5.0V, VBAT=3V, STB13 ~ 7=3V,UPIC8=2.5V)
Parameter Symbol Limits Unit Conditions
Min. Typ. Max.
【Internal regulator VREGA】
Output voltage VREGA 2.4 2.5 2.6 V Io=5mA
【Low-voltage input malfunction prevention circuit 】
Detecting voltage 1 Vstd1 - 2.0 2.3 V VREGA monitor
Hysteresis width 1 ⊿Vstd1 50 100 200 mV
Detecting voltage 2 Vstd2 - 2.4 2.5 V VCCOUT monitor
Hysteresis width 2 ⊿Vstd2 100 200 300 mV
【Short-circuit protection circuit】
SCP detecting time Tscp 20 25 30 msec
Timer start threshold voltage Vtcinv 0.38 0. 48 0.58 V INV terminal monitor
CH3 ~ 5
【Start circuit】
Oscillating frequency Fstart 150 300 600 kHz
Operation initiation VBAT voltage Vst1 1.5 - - V
Start-up CH soft start time Tss1 1.8 3.0 5.3 msec
【Oscillating circuit】
Oscillating frequency CH1 ~ 5 fosc1 1.0 1.2 1.4 MHz
Oscillating frequency CH6 ~ 8 fosc2 0.5 0.6 0.7 MHz
Max duty 2,3,4,5(voltage step-down) Dmax1d - - 100 % (※2)
Max duty 1(voltage boost) Dmax1u 86 92 96 %
Max duty 6,7,8 Dmax2 86 92 96 %
【Error AMP】
Input bias current IINV - 0 50 nA INV1 ~ 8, NON5=3.0V
INV threshold 1 VINV1 0.79 0.80 0.81 V CH1 ~ 5
INV threshold 2 VINV2 0.99 1.00 1.01 V CH7,8V
INV threshold 3 (max) VINV3 370 400 430 mV CH8I
【Base Bias Voltage Vref for inverted Channel】
CH6 output voltage VOUT6 -6.09 -6.00 -5.91 V NON6 12kΩ, 72kΩ(※3)
Line regulation DVLi - 4.0 12.5 mV VCCOUT=1.5 ~ 5.5V
Output circuit at the time of short-circuit Ios 0.2 1.0 - mA Vref=0V
【Soft start】
CH2, 5 soft start time Tss2, 5 3.4 4.4 5.4 msec
CH3, 4 soft start time Tss3, 4 1.2 2.2 3.2 msec
CH6 soft start time Tss6 3.4 4.4 5.4 msec
CH7, 8 soft start time Tss7, 8 4.4 5.4 6.6 msec
※2 The protective circuit start working when circuit is operated by 100% duty.
So it is possible to use only for transition time shorter than charge time for SCP.
※3 Recommend resistor value over 20kΩ between VREF to NON6, because VREF current is under 100µA.
◎ This product is not designed for normal operation within a radioactive environment.
Technical Note
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BD9757MWV
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●Electrical characteristics (Unless specified, Ta=25℃, VCCOUT=5.0V, VBAT=3V, ST B13 ~ 7=3V,UPIC8=2.5V)
Parameter Symbol Limits Unit Conditions
Min. Typ. Max.
【Output Driver】
CH1 High side switch ON resistance RON1p - 120 270 mΩ Hx1=5V
CH1 Low side switch ON resistance RON1N - 80 240 mΩ VCCOUT=5.0V
CH2 High side switch ON resistance RON21p - 250 400 mΩ Hx2=5V
CH2 Low side switch ON resistance RON21N - 250 400 mΩ VCCOUT=5.0V
CH3 High side switch ON resistance RON3p - 250 400 mΩ Hx3=3V ,
VCCOUT=5V
CH3 Low side switch ON resistance RON3N - 250 400 mΩ VCCOUT=5.0V
CH4 High side switch ON resistance RON4p - 250 400 mΩ Hx4=3V,
VCCOUT=5V
CH4 Low side switch ON resistance RON4N - 250 400 mΩ VCCOUT=5.0V
CH5 High side switch ON resistance RON5p - 250 400 mΩ Hx5=5V
CH5 Low side switch ON resistance RON5N - 150 300 mΩ VCCOUT=5.0V
Output voltage H at the time of CH6 driving Vout6H VCCOUT
-1.5 VCCOUT
-1.0 - V
IOUT6=50mA
NON6=0.2V
Output voltage L at the time of CH6 driving Vout6L - 0.5 1.0 V IOUT6=-50mA,
NON6=-0.2V
CH7,8 NMOS switch ON resistance RON7,8N - 500 800 mΩ VCCOUT=5.0V
CH7,8 load switch ON resistance RON7,8p - 200 350 mΩ HS7,8H=3V ,
VCCOUT=5.0V
【STB1 ~ 7】
STB control voltage operating VSTBH1 1.5 - 5.5 V
Non-operating VSTBL1 -0.3 - 0.3 V
Pull down resistance RSTB1 250 400 700 kΩ
【UPIC8】
UPIC8
Control voltage H level VUPIH 2.1 - 4.00 V
L level VUPIL 0 - 0.40 V
Pull down resistance RUPIC1 30 50 80 kΩ
【Circuit current】
Circuit current at the
time of standby
VBAT terminal ISTB1 - - 5 μA
HS7,8H terminal ISTB4 - - 5 μA
Hx terminal ISTB2 - - 5 μA Voltage step-down
Lx terminal ISTB3 - - 5 μA Voltage boost
Circuit current at the time of Start-up
(VBAT terminal inflow current) IST - 150 450 μA VBAT=1.5V
Circuit current 1 at the time of operating
(VBAT terminal inflow current) Icc1 - 45 150 μA VBAT=3.0V
Circuit current 2 at the time of operating
(VCCOUT appli ed terminal inflo w current) Icc2 - 5.0 9.7 mA
INV1 ~ 8=1.2V ,
NON6=-0.2V
◎ This product is not designed for normal operation within a radioactive environment.
Technical Note
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●Reference data (1)
Fig.3 Frequency CH6 ~ 8-Temp
Fig.2 Frequ ency CH1 ~ 5-Temp
Fig.5 CH6 Base voltage-Temp
Fig.7 CH2
3.2V step-down efficiency-Io
Fig.11 CH6
-6V inverting efficiency-Io
Fig.1 Start-up circuit frequency-Temp
Fig.4 VREGA output voltage-Temp
Fig.6 CH1
5.0V voltage boost efficiency-Io Fig.8 CH2
3.2V step-down efficiency-Io
Fig.9 CH4
1.8V step-down efficiency-Io Fig.10 CH5
3.5V step-down efficiency-Io
0
100
200
300
400
500
600
-40 -20 0 20 40 60 80 100
Ta [℃]
freq[KHz]
Start-up circuit operating frequency temperature characteristic
1.00
1.05
1.10
1.15
1.20
1.25
1.30
1.35
1.40
-40-200 20406080100
Ta [℃]
freq[MHz]
Current mode operating frequency temperature characteristic Voltage mode operating frequency temperature charac teristic
500
520
540
560
580
600
620
640
660
680
700
-40 -20 0 20 40 60 80 100
Ta [℃]
freq[KHz]
2.40
2.42
2.44
2.46
2.48
2.50
2.52
2.54
2.56
2.58
2.60
-40 -20 0 20 40 60 80 100
Ta [℃]
VREGA [V]
VREGA output voltage temperat ure characteristic
0.94
0.96
0.98
1.00
1.02
1.04
1.06
-40 -20 0 20 40 60 80 100
Ta [℃]
VREF6 [V]
VREF6 output voltage temperatur e characteristic
60
65
70
75
80
85
90
95
100
10 100 1000 10000
Load current[mA]
Efficiency
Vin=1.5V
Vin=2.4V
Vin=3.6V
Vin=4.2V
CH1 boost 5.0 efficiency data
50
55
60
65
70
75
80
85
90
95
100
10 100 100
0
Vin=3.6V
Vin=4.2V
Vin=4.8V
Vin=5.5V
CH2 step-down 3.2V efficiency data
Efficiency
Load current[mA]
40
45
50
55
60
65
70
75
80
85
90
95
100
10 100 1000
Vin=1.5V
Vin=2.4V
Vin=3.6V
Vin=4.2V
Vin=5.5V
CH3 step-down 1.2V efficiency data
Load current [mA]
Efficiency
40
45
50
55
60
65
70
75
80
85
90
95
100
10 100 1000
Vin=2.4V
Vin=3.6V
Vin=4.2V
Vin=5.5V
CH4 step-down 1.8V efficiency data
Efficiency [%]
Load current [mA]
50
55
60
65
70
75
80
85
90
95
100
10 100 1000
Vin=4.2V
Vin=4.8V
Vin=5.5V
CH5 step-down 3.5V efficiency data
Efficiency [%]
Load current [mA]
40
50
60
70
80
90
100
110100
Vin=2.4V
Vin=3.6V
Vin=4.2V
Vin=5.5V
CH6 Reversal -6V efficiency data
Load current [mA]
Efficiency [%]
Technical Note
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●Reference data (2)
STB13
Vo1
Fig.14 CH1 start-up waveform
(VBAT=1.5V) Fig.15 CH1,3 start-up waveform
(VBAT=3.0V) Fig.16 CH2 start-up waveform
Inflow current(1A/Div)
STB13
Vo1
Vo3
Inflow current (1A/Div)
STB2
Vo2
Inflow current (1A/Div)
Fig.17 CH4 start-up waveform Fig.18 CH5 start-up waveform Fig.19 CH6 start-up waveform
STB4
Vo4
Inflow current (1A/Div)
STB5
Vo5
Inflow current(1A/Div)
STB6
Vo6
Inflow current (1A/Div)
Fig.20 CH7 start-up waveform Fig.21 CH8 start-up waveform
STB7
Vo7
Inflow current (1A/Div)
UPIC8
Vo8
Inflow current (1A/Div)
Fig.12 CH7 12V boost efficiency-Io Fig.13 CH8 LED boost efficiency-Io
40
50
60
70
80
90
100
110100
Vin=1.5V
Vin=2.4V
Vin=3.6V
Vin=4.2V
Vin=5.5V
CH7 boost12V efficiency data
Load current [mA]
Efficiency [%]
70
75
80
85
90
95
100
0123456
Io=7.5mA
Io=12.5mA
Io=17mA
Io=20mA
Efficiency [V]
Input voltaage [V]
CH8 LED efficiency data
Technical Note
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BD9757MWV
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●Pin Assignment
Fig.22 BD9757MWV Top VIEW
●Pin Description
PIN No. PIN name I/O Function Notes
21 VBAT I Battery voltage input Starting up at
higher than 1.5V
28 VCCOUT I Power supply input terminal Connecting
the CH1 output
26 GND - Earth terminal
15,16,7,2,39 PGND13,24,5, 678 - Earth terminal with built-in FET
27 VREGA O VREGA output 2.5V output
30 VREF6 O reference voltage output for CH6 inversion 1.0V output
41 OUT6 O CH6 PMOS gate connection terminal
19,20,5,13,9,4 Hx1,2,3,4,5 O Synchro nous rectification high side switch
input terminal, Pch Driver power supply output
17,18,6,14,8,3,40,38 Lx1,,2,3,4,5,7,8 O Inductor connection terminal
36 HS78H I
Built-in load switch power supply input
terminal
35,37 HS7L,HS8L O Built-in load s witch output terminal
22,25,23,24,29,32,34 INV1,2,3,4,5,7,8 I Error amplifier inversion input terminal
31 NON6 I Error amplifier non-inversion input terminal
33 INV8I I Error amplifier inversion input terminal
12,10,11,1,44,43 STB13,2,4,5,6,7 I
CH1 ~ CH7 ON / OFF switch
Operating :higher than 1.5V At the time of All Low
Standby state
42 UPIC8 I
CH8 start-up signal, LED light
control-purpose signal input
34
35
36
37
38
39
40
41
42
43
44
22
21
20
19
18
17
16
15
14
13
12
12345678910
11
33 32 31 30 29 28 27 26 25 24 23
INV8
HS7L
HS78H
HS8L
LX8
PGND678
LX7
OUT6
UPIC8
STB7
STB6
VBAT
HX1
LX1
LX1
HX1
PGND13
PGND13
LX3
HX3
STB13
INV1
BD9757MWV
STB5
PGND5
LX5
HX5
HX2
LX2
PGND24
LX4
HX4
STB2
STB4 INV3
INV4
INV2
GND
VCCOUT
VREGA
INV5
VREF6
NON6
INV7
INV8I
Technical Note
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●Application circuit (1)
Fig.23 Applied circuit diagram 1(lithium 1 cell)
○Operation notes
・we are confident that the above applied circuit diagram should be recommended, but please thoroughly confirm its characteristics when using it. In
addition, when using it with the external circuit’s constant changed, please make a decision that allows a sufficient margin in ligh t of the fluctu ations of
external components and ROHM’s IC in terms of not only static characteristic but also transient characteristic.
Technical Note
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●Application circuit (2)
Fig.24 Applied circuit diagram 2(dry battery ×2)
○Operation notes
・we are confident that the above applied circuit diagram should be recommended, but please thoroughly confirm its characteristics when using it. In
addition, when using it with the external circuit’s constant changed, please make a decision that allows a sufficient margin in ligh t of the fluctu ations of
external components and ROHM’s IC in terms of not only static characteristic but also transient characteristic.
Technical Note
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●Timing chart (1)
STB13,
STB2
CH1
CH3
CH2
Tss1
STB4, STB5
CH4
Tss3
Tss2
Tss4
Tss5
CH5
Tss1 Abou t 3.0msec
Tss3 Abou t 2.2msec
Tss2 Abou t 4.4msec
Tss4 About 2.2msec
Tss5 About 4.4msec
After finished CH1 rise,
other CH start rise.
When CH1 is already risen,
CH is start up with STB rise.
Fig.25 CH1 ~ 5 start-up sequence
STB6, STB7
CH6
reverse output Tss6
CH7
output
Tss7
Tss6 About4.4msec
Tss7 About5.4msec
Fig.26 CH6, 7 start-up sequence
Technical Note
11/20
BD9757MWV
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●Timing chart (2)
Fig.27 CH8 start-up sequence
UPIC8
LED current
A
bout 5.4msec
Interval of soft start
Interval of modulated light setting
LED current is adjusted according to the set number of counts
Soft start is started
according to setting
Vo8
It is returned immediately if the set voltage is exceeded
Tss8 Tss8 Oscillating frequency=6400counts
about 5.4msec
Technical Note
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BD9757MWV
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●Block explanation
1. VREGA
It is a regulator with output voltage of 2.5V and used as a power supply of internal block. In addition, it outputs to
outside from VREGA terminal (32pin). 1.0μF is recommended as an external capacitor for oscillation prevention.
2. SCP, Timer Latch
It is a timer latch type of short-circuit protection circuit.
For CH1,2, 6 ~ 8, the error AMP output voltage is monitored, and detected when the feedback voltage deviates from
control, for CH3 ~ 5, it is detected when the voltage of INV terminal becomes lower than 80%, and in 25ms the latch
circuit operates and the outputs of all the channels are fi xed at OFF.
In order to reset the latch circuit, please turn off all the STB terminals before turning them on once again or turning
power supply on once again.
3. U.V.L.O (Under Voltage Lockout)
It is a circuit to prevent malfunction at low voltage.
It is to prevent malfunction of internal circuit at the time of rising or dropping to a lower value of power supply voltage.
If the voltage of VCCOUT terminal becomes lower than 2.4V, then the output of each DC/DC converter is reset to OFF,
and SCP’s timer latch & soft start circuit are reset. When control is deviated from, the operation of CH1 at the time of
start-up will be explained in START UP OSC mentioned later.
4. Voltage Reference (VREF6)
For the reference voltage circuit of CH6 inversion CH, the output voltage is 1V and outputted from VREF6 terminal
(30pin). According this voltage and the output voltage of CH6, the dividing resistance (resistor) is set and then the
output voltage is set. If STB6 terminal is made to be H level at the time of start-up, then increase graduall y the voltage
up to 1V. The inversion output of CH6 follows this voltage and performs the soft start. 1.0μF is recommended as the
external capacitor.
5. OSC
It is an oscillation circuit the frequency of which is fixed by a built-in CR.
The operating frequencies of CH1 ~ CH5 are set at 1.2MHz, and the operating frequencies of CH6 ~ CH8 are set at
600kHz.
6. ERRAMP 1 ~ 8
It is an error amplifier to detect output signal and output PWM control signal. The reference voltages of ERRAMP
(Error Amplifier) of CH1, 2,3,4,5 are internally set at 0.8V, and the reference voltages of ERRAMP (Error Amplifier) of
CH7.8 are set at 1.0V. The reference voltage of CH6 is set at GND potential, and for CH8’s ERRAMP81, the maximum
value of the reference voltage is set at 0.4V. In addition, each CH incorporates a built-in element for phase
compensation.
7. ERRCOMP , Start Up OSC
It is a comparator to detect the output voltage and control the start circuit, and also an oscillator that is turned ON/OFF
by this comparator and starts oper ating from 1.5V. The frequency of this oscillator is about 300 kHz fixed internall y. This
oscillator stops operating if VCC terminal becomes more than 2.6V or the soft start time is exceeded.
8. Current mode control block
CH1 ~ 5 adopt the PWM method based on current mod e.
For a current- mode DC/DC converter, FET at the main side of synchronous rectification is turned on when detecting
the CLK’s edge, and turned off by detecting the peak current by means of the current comparator.
9. PWM COMP
PWM converter is a voltage-pulse width converter to control output voltage according to input voltage. It compares the
output voltage of error amplifier with the SLOPE waveform, controls the pulse width and outputs to driver. The driver is
turned on during the output of error amplifier being higher than SLOPE waveform. The maximum ON duty is set at
about 92% internally.
Technical Note
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BD9757MWV
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10. Nch DRIVER , Pch DRIVER
It is a CMOS inverter type of output circuit to drive both built-in and external Nch,Pch FET.
11. Load switch
It is a circuit, mounted in CH7, 8, to control the Load switch. HS78H terminal (36pin) is input terminal, and the HS67
and HS78 terminals (40,37pin) are output terminals.
This control circuit can prevent the rush current at the time of s witch ON because the soft start starts functioning at the
time of start-up. In addition, this Load switch is provided with OCP function to prevent the IC from damage.
Ensure that the IC is used within Load switch’s rated current when used normally.
12. ON/OFF LOGIC
It is the voltage applied to STB terminal and can control the ON/OFF of CH1 ~ CH7.
If the voltage more than 1.5V is applied, then it becomes ON, but if open or 0V is applied, then it becomes off,
furthermore, it all the channels are turned off, then the whole IC will be in standby state. In addition, STB13 ~ STB7
terminals contain respectively a built-in pull-down resistor of about 400kΩ. UPIC8 is the input terminal of the start signal
and the light control signal of CH8. It becomes High if the voltage more than 2.1V is applied and becomes Low if the
voltage less than 0.4V is applied. In addition, UPIC8 terminal contains a built-in pull-down resistor of about 50kΩ.
13. SOFT START
It is a circuit to apply the soft start to the output voltage of DC/DC converter and prevent the rush current at the start-up.
Soft start time varies with the channels.
a. CH1 ・・・・・ Reaches the target voltage in 3.0 msec.
b. CH3,4 ・・・・・ Reaches the target voltage in 2.2 msec.
c. CH2,5,6 ・・・・・ Reaches the target voltage in 4.4 msec.
d. CH7,8 ・・・・・ Reaches the target voltage in 5.4 msec.
Technical Note
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BD9757MWV
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●CH8 Modulated light function explanation
○Description of CH8 operation
EN, the signal for getting CH8 operated, is turned to H (EN=H) by maintaining the H interval that is shown by TEN and
from UPIC8 terminal (refer to Fig.29 EN start-up-G) .
EN signal is turned to L and CH8 is turned OFF by maintaining the L interval that is shown by TOFF and from UPIC8
terminal (refer to Fig.29 EN start-up-K ~ L) .
Moreover, UPIC8 terminal will not bec ome L ever since EN starting-up, and if the H interv al sho wn b y TON is passed, then
the DAC input data (DACIN [4:0]) for setting of INV8I output voltage is started up by the state of MAX voltage setting (1Fh)
(refer to Fig.29 FULLON Mode-H ~ I).
As for the method to set the values except MAX voltage as INV8I voltage, first fix the UPIC8 terminal on interv al L shown
by TCLR and then reset the counter for tone setting, before inputting only the number of times equivalent to the tone
intended for setting the UPIC8 terminal’s rising edge. Right after that, if it is fixed on interval H shown by TON, then the
number of count is latched, transmitted to DAC, and the voltage of INV8I is switched to the set voltage. At the time of
setting again, please repeat this operation (procedure). For the frequency of pulse inputted to UPIC8 terminal, please
follow the rules of TH and TL. (refer to Fig.29 Normal mode-K ~ N, and refer to P.2 for the rules).
Once the counter for tone setting reaches 31, 1Fh remains unchanged no matter how many times it is counted. If the
counter for tone setting needs to be cleared, please input the interval L of TCLR.
If the pulses less than TCLR is continued to be inputted to UPIC8 terminal after EN becomes H (EN=H) at the time of
starting up, then the value of counter for tone setting is undetermined, and DAC for INV8I output voltage setting is turned
OFF, therefore, please determine the set value with the time shown by TSET .
Furthermore, for the possible setting range of INV8I output voltage value, please refer to P.16(Fig.30 LED current value
setting).
○Points for attention at the time of CH8 starting up
Soft start is started when light control setting signal is inputted from UPIC8 terminal. At this moment it is necessary to
make any one of ST B1 ~ 7 to be H, if OSC does not start oscillating after VREGA is started and UVLO is released, then
CH8 does not start up.
At the time of starting up there is no voltage enough for turning ON the LED, so the feedback on the side of INV8I does
not return,and it is soft-started by the voltage feedback from Vo8 to INV8.
Before the soft start internal is ended, the feedback (return) based on any current setting which is according to light
control setting is started. After soft-starting, any current setting is performed by changing the light control setting signal.
CH8 is turned off by making UPIC8 terminal to be L for a certain period of time.
Moreover, the interval of about 5.4mS from the time of UPIC8 terminal’s rising is taken as the soft start interval, and the
soft start is applied according to the current value origin ally set by light control from UPIC8 terminal. The change of li ght
control setting excepting turning off during this interval is not reflected.
○Recommended method of setting at the time of INV8I output voltage setting
If INV8I output setting value is made larger than previous setting value during all intervals but soft start interval (at the
time of starting up), it is recommended that the value of vol tage is increased step b y step with the smallest possible width
of step after fully evaluating the restriction at the soft side that controls rush current and switching and the vision of
brightness etc. in terms of set application.
+
-
+
+
-
++
-
+
OSC
PWM COMP8
ERRAMP 8I
ERRAMP 8V
N-ch
DRIVER
VCCOUT
Load
SW
VCCOUT
OCP
HS78H
INV8I
VBAT
Vo8(Feed Back ch8)
LED
SOFT
START
DAC
EN
STBY
UVLO SS_CLK
EN
INV8
INV8I
UPIC8
PGND678
Lx8
HS8L
HS78H
To SCP
1.0V
EN
LOGIC
DACIN[5:0]
counter for
tone setting
reaches 31
(5bit)
VREGA_D
Detect Count er
for H Section
(6bit)
COUNT[4:0] latch
VREGA1
S
E
L
5->6bit
decode
1Fh(Fixed)
P&R area
RESET
GEN
UVLO
I/O
(schmitt) LED Current
setting resister R
Detect Counter
for L Section
(6bit)
Fig.28 CH8 block diagram
Technical Note
15/20
BD9757MWV
www.rohm.com 2010.11 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
●Explanation o n o peration of CH8 5bit Counter + Register
Fig.29 Ti ming chart
Technical Note
16/20
BD9757MWV
www.rohm.com 2010.11 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
UPIC8
rising edge count DAC input
DACIN[4:0] INV8I
output voltage [V]
1 01h 0.100
2 02h 0.110
3 03h 0.120
4 04h 0.130
5 05h 0.140
6 06h 0.150
7 07h 0.160
8 08h 0.170
9 09h 0.180
10 0Ah 0.190
11 0Bh 0.200
12 0Ch 0.210
13 0Dh 0.220
14 0Eh 0.230
15 0Fh 0.240
16 10h 0.250
17 11h 0.260
18 12h 0.270
19 13h 0.280
20 14h 0.290
21 15h 0.300
22 16h 0.310
23 17h 0.320
24 18h 0.330
25 19h 0.340
26 1Ah 0.350
27 1Bh 0.360
28 1Ch 0.370
29 1Dh 0.380
30 1Eh 0.390
31 1Fh 0.400
Fig.30 LED current setting
(Note 1) LED current = INV8I voltage / resistance R for LED current setting
Technical Note
17/20
BD9757MWV
www.rohm.com 2010.11 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
●Setting method of IC peripheral components
(1) Design of feedback resistor constant
CH1～5 output voltage CH6 output voltage
(1)]V[8.0
2R 2R1R
VO・・・
(2)]V[0.1
1R2R
VO・・・
CH7,8 output voltage CH8 output voltage
(3)]V[0.1
2R 2R1R
VO・・・
(4)]A[
3R I8INV
IO・・・
Fig.31 Feedback resist or setting method
(a) CH1 ~ 5 setting
The reference voltage of CH1 ~ 5’s ERROR AMP is 0.8V. Please refer to Formula (1) in Fig.31 for determining the
output voltage.
This IC incorporat es built-in phase compensation. Please r efer to Applied Circuit Diagram for setting t he values of R1
& R2 and ensure that the setting values of R1 & R2 are of the order of several hundred kΩ.
(b) CH6 setting
The reference voltage of CH6’s ERROR AMP is connected to GND inside the IC. Therefore, a high-accuracy
regulator can be config ured if set ting b y the feedback resistance b et ween the outp uts of VREF and CH5 as sho wn in
Fig.31. Please refer to Formula (2) in Fig.31 for determining the output voltage. R1 is recommended as more than
20kΩ because the current capacity of VREF is about 100μA.
(c) CH7 setting
The reference voltage of CH7’s ERROR AMP is 1.0V. Please refer to Formula (3) in Fig.31 for determining the output
voltage.
(d) CH8 setting
In the CH8 there are two ERROR AMPs which have different standards, and when used with constant current
feedback applied unilaterally to backlight etc. , the over voltage protection can be operated unilaterally.
Over voltage setting and output current setting are respectively shown in Formula (3) and (4) in Fig.31.
The outputs of these two ERROR AMPs are controlled with L being given priority.
Therefore, when used under the control of only either of the two ensure that the INV terminal is used as GND Short.
CH6, CH7, and CH8 are of voltage mode control. Ensure that CH6, 7 and 8 are used by means of discontinuous
inductor current so as to secure the oscillation margin.
(2) Points for attention in terms of PCB layout of base-plate
○For a switching regulator, in principle a larg e current tr ansient l y flo ws through the ro ut e of po wer supply - coil - output
capacitor. Ensure that the wiring impedance is lowered as much as possible by making the pattern as wide as
possible and the layout as short as possible.
○Interference of power supply noise with feedback terminals (INV1 ~ 8I,NON6) may cause the output voltage to
oscillate. Ensure that the power supply noise’s interference is avoided by making the wiring between feedback
resistor and feedback terminal as short as possible.
VREF
1.0V
VOUT7
ERROR AMP
R1
R2
INV
Reference voltage is
connected to GND inside IC
VREF6
ERROR AMP
R1
R2
NON
VOUT6 VREF
0.8V
VOUT1～5
ERROR AMP
R1
R2
INV
VOUT8
VREF
1.0V
ERROR AMP8V
R1
R2
INV8
VREF
ERROR AMP7I
R3
INV8I
UPIC8 Setting according to
number of counts
(Refer to Fig.29 of page 15)
Output level
L takes priority
Technical Note
18/20
BD9757MWV
www.rohm.com 2010.11 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
●PIN equivalent circuit
Fig.32 PIN equivalent circuit
INV1～INV8,INV8I
(Error amplifier’s inversion input) NON6
(Error amplifier’s non-inversion input)
VREGA (REGA output) VREF6
(CH6 Standard voltage output)
STB13, STB2, STB4, STB5,
STB6, STB7 (Operating when
CH1~7 ON/OFF switch is High)
Hx1,2,3,4,5(Pch FET source terminal)
Lx1,2,3,4,5(Nch,Pch FET drain terminal)
PGND13,24,5 (output stage earthing terminal)
Lx7, 8 (Nch FET drain terminal)
PGND678
HS78H (high side SW input terminal)
HS7L, 8L (high side SW output terminal) OUT5(CH5 power-MOSFET connection)
PGND567 (output stage earthing)
UPIC8
(CH8 start signal, LED
modulated light signal input)
VCCOUT
VREGA
VCCOUT VREGA VCCOUT
VREF6
VCCOUT
INV
VREGA VCCOUT
NON6
VREGA
VCCOUT
STB VCCOUT
PGND
Lx
Hx
HS78H
HS7L,8L
Lx7,8
PGND678
VCCOUT
OUT6
VCCOUT
PGND678
VCCOUT VCCOUT
VREGA
UPIC8
Technical Note
19/20
BD9757MWV
www.rohm.com 2010.11 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
●Notes for use
1.) Absolute Maximum Ratings
Although the q ualit y of this pr oduct h as bee n t ightl y c ont rol led, d et erior ati on or even des t ruct ion ma y oc cur if t he a bsol ute
maximum ratings, such as for applied press ure and operational t emperature range, are exceeded. F urthermore, we are
unable to assume short or open mode destruction conditions. If special modes which exceed the absolute maximum
ratings are expected, physical safely precautions such as f uses should be considered.
2.) GND Potential
The potential of the GND pin should be at the minimum potentia l during all operation status. In addition, please try to do
not becom e electric potential below GND for t he terminal other than NON6 including the transient phenomenon in practice.
Please do not go down below 0.3V for the NON6 t erminal with transient phenomenon and the like when you use.
3.) Heat Design
Heat design should consider t olerance dissipation (Pd) during actual use and marg ins which should be set with plenty of
room.
4.) Short-circuiting Between Terminals and Incorrect Mount ing
When attaching to the printed substrat e, pay special attention to the direction and proper placement of the IC. If the IC is
attached incorrectly, it may be destroyed. Destruction can also occur when there is a short, which can be caused by
foreign objects entering between ouputs or an output and the power GND.
5.) Operation in Strong Magnetic Fields
Exercise caution when operating in st rong magnet fields, as errors can occur.
6.) About common impedance
Please do sufficient consid eration for the wiring of po wer source and GND with the measures such as l owering common
impedance, making ripple as small as possible (making the wiring as thick and short as possible, dropping ripple from
L.C) and the lik e.
7.) STB terminal voltage
Please set STB terminal voltage below 0.3V when each chan nel is put in stand-by state, and set it above 1.5V when each
channel is put in working condition. Please use the condenser below 0.01μF when the condenser is connected to the
STB terminal. As it will beco m e the cause of the malfunction.
8.) Heat Protection Circuit (TSD circuit)
This IC has a built-in Temperature Protectio n Circuit (TSD circuit). T he temperature protection circuit (T SD circuit) is only
to cut off the IC from thermal runaway, and has not been designed to protect or guarantee the IC. Therefore, the user
should not plan to activate this circuit with continued operation in mind.
9.) Because there are times when rush current flows instantaneously in internal logical uncertain state at the time of power
source turning on with CMOS IC, please pay attention to the power source coupling capacity, the width of GND pattern
wiring and power source, and the reel.
10.) Because there are times when rush current f lows instantaneously due to t he order of power source throwing in, lag with
CMOS IC where it has plural power sources, please pay attention to the power source coupling capacity, the width of
GND pattern wiring and power source, and the reel.
11.) IC Terminal Input
This IC is a monolithic IC, and between each element there is a P+ isolation and P substrate for element separation.
There is a P-N junction formed between this P-layer and each element’s N-layer, which makes up various parasitic
elements. For exam ple, when resistance and transistor are connected with a terminal as in Fi g.33:
○When GND>(terminal A) at the resistance, or GND>(terminal B) at the transistor (NPN),
the P-N junction operates as a parasitic diode.
○Also, when GND>(terminal B) at the transistor, a parasiti c NPN transistor operates by the N-layer of other el ements
close to the aforement ioned parasitic diode.
With the IC’s configuration, the production of parasitic elements by the relationships of the electrical potentials is
inevitable. The operation of the parasitic elements can also interfere with the circuit operation, leading to malfunction
and even destruction. Therefore, uses which cause the parasitic elements to operate, such as applying voltage to the
input terminal which is lower than the GND (P-substrate), should be avoided.
Fig.33 Simple Structure of Bipolar IC (Sample)
(Terminal A)
Parasitic Element
Transistor (NPN)
GND
P Board
N P
N N
P+
P+
(Terminal B) B
N
E
C
GND (Terminal A)
GND
Parasitic Element
GND
P Board
N P
N N
P+
P+
Parasitic Element
Resistance
～
～
Technical Note
20/20
BD9757MWV
www.rohm.com 2010.11 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
●Ordering part number
B D 9 7 5 7 M W V - E 2
Part No. Part No.
Package
MWV: UQFN044V6060 Packaging and forming specification
E2: Embossed tape and reel
(Unit : mm)
UQFN044V6060
0.08 S
S
1PIN MARK
2333
34
44 12
111
22
0.02+0.03
-
0.02
0.2+0.05
-
0.04
C0.2
0.4
1.0
6.0±0.1
3.7±0.1
0.5±0.1
3.7±0.1
6.0±0.1
1.0MAX
(0.22)
∗
Order quantity needs to be multiple of the minimum quantity.
<Tape and Reel information>
Embossed carrier tapeTape
Quantity
Direction
of feed
The direction is the 1pin of product is at the upper left when you hold
reel on the left hand and you pull out the tape on the right hand
2000pcs
E2
()
Direction of feed
Reel 1pin
Datasheet
Datasheet
Notice - GE Rev.002
© 2014 ROHM Co., Ltd. All rights reserved.
Notice
Precaution on using ROHM Products
1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), transport
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN USA EU CHINA
CLASSⅢ CLASSⅢ CLASSⅡb CLASSⅢ
CLASSⅣ CLASSⅢ
2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3. Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4. The Products are not subject to radiation-proof design.
5. Please verify and confirm characteristics of the final or mounted products in using the Products.
6. In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7. De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8. Confirm that operation temperature is within the specified range described in the product specification.
9. ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1. When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2. In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Datasheet
Datasheet
Notice - GE Rev.002
© 2014 ROHM Co., Ltd. All rights reserved.
Precautions Regarding Application Examples and External Circuits
1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2. You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1. Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2. Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3. Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4. Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
QR code printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHM representative in case of export.
Precaution Regarding Intellectual Property Rights
1. All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data. ROHM shall not be in any way responsible or liable
for infringement of any intellectual property rights or other damages arising from use of such information or data.:
2. No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the information contained in this document.
Other Precaution
1. This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2. The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3. In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4. The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
DatasheetDatasheet
Notice – WE Rev.001
© 2014 ROHM Co., Ltd. All rights reserved.
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3. The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
