TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D
50-mA Low-Dropout Regulator
D
Available in 1.5-V, 1.8-V, 2.5-V, 2.8-V, 3.0-V
D
Output Noise Typically 56 µVRMS
(TPS79030)
D
Only 17 µA Quiescent Current at 50 mA
D
1 µA Quiescent Current in Standby Mode
D
Dropout Voltage Typically 57 mV at 50 mA
(TPS79030)
D
Over Current Limitation
D
–40°C to 125°C Operating Junction
Temperature Range
D
5-Pin SOT-23 (DBV) Package
description
The TPS790xx family of low-dropout (LDO)
voltage regulators offers the benefits of
low-dropout voltage, ultralow-power operation,
low-output noise, and miniaturized packaging.
These regulators feature low-dropout voltages
and ultralow quiescent current compared to
conventional LDO regulators. An internal resistor ,
in conjunction with an external bypass capacitor,
creates a low-pass filter to reduce the noise. The
TPS79030 exhibits only 56 µVRMS of output
voltage noise using 0.01 µF bypass and 10 µF
output capacitors. Offered in a 5-terminal small
outline integrated-circuit SOT-23 package, the
TPS790xx series devices are ideal for
micropower operations, low output noise, and
where board space is limited.
The usual PNP pass transistor has been replaced
by a PMOS pass element. Because the PMOS
pass element behaves as a low-value resistor, the
dropout voltage is very low, typically 57 mV at
50 mA of load current (TPS79030), and is directly
proportional to the load current. The quiescent
current is ultralow (17 µA typically) and is stable
over the entire range of output load current (0 mA
to 50 mA). Intended for use in portable systems
such as laptops and cellular phones, the
ultralow-dropout voltage feature and ultralow-
power operation result in a significant increase in
system battery operating life.
Copyright 2001, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
3
2
4
5
DBV PACKAGE
(TOP VIEW)
1
IN
GND
EN
OUT
BYPASS
0
200
400
600
800
1000
1200
100 1k 10k 100k
f – Frequency – Hz
VI = 4 V
Co = 4.7 µF
C(byp) = 0.1 µF
TPS78930
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
IO = 1 mA
IO = 50 mA
V/ HzOutput Spectral Noise Density –
µ
TJ – Junction Temperature – °C
15
22
TPS79030
GROUND CURRENT
vs
JUNCTION TEMPERATURE
Ground Current – Aµ
VI = 4 V
Co = 4.7 µF
21
20
19
18
17
16
IO = 1 mA
IO = 50 mA
–40 5–25 20 35 65 110 12550–10 80 95
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
2POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description (continued)
The TPS790xx also features a logic-enabled sleep mode to shut down the regulator, reducing quiescent current
to 1 µA typical at TJ = 25°C. The TPS790xx is offered in 1.5 V, 1.8 V, 2.5 V, 2.8 V, 3.0 V.
AVAILABLE OPTIONS
TJVOLTAGE PACKAGE PART NUMBER SYMBOL
1.5 V TPS79015DBVT†TPS79015DBVR‡PEBI
1.8 V
SOT 23
TPS79018DBVT†TPS79018DBVR‡PECI
–40°C to 125°C2.5 V
SOT
-
23
(DBV)
TPS79025DBVT†TPS79025DBVR‡PEDI
2.8 V
(DBV)
TPS79028DBVT†TPS79028DBVR‡PEEI
3.0 V TPS79030DBVT†TPS79030DBVR‡PEFI
†The DBVT indicates tape and reel of 250 parts.
‡The DBVR indicates tape and reel of 3000 parts.
functional block diagram
TPS79015/18/25/28/30
OUT
IN
GND
EN
Vref
Current Limit
/ Thermal
Protection
Bypass
150 kΩ
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME NO.
I/O
DESCRIPTION
BYPASS 4 I Bypass
EN 3 I Enable input
GND 2 Ground
IN 1 I Input supply voltage
OUT 5 O Regulated output voltage
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
detail description
The TPS790xx uses a PMOS pass element to dramatically reduce both dropout voltage and supply current over
more conventional PNP-pass-element LDO designs. The PMOS pass element is a voltage-controlled device
and, unlike a PNP transistor, it does not require increased drive current as output current increases. Supply
current in the TPS790xx is essentially constant from no load to maximum load.
The TPS790xx family of low-dropout (LDO) regulators have been optimized for use in battery-operated
equipment. They feature extremely low dropout voltages, low output noise, low quiescent current (17 µA
typically), and enable inputs to reduce supply currents to 1 µA when the regulators are turned off.
The internal voltage reference is a key source of noise in a LDO regulator. The TPS790xx has a BYPASS pin
which is connected to the voltage reference through a 150-kΩ internal resistor. The 150-kΩ internal resistor,
in conjunction with an external bypass capacitor connected to the BYPASS pin, creates a low pass filter to
reduce the voltage reference noise and, therefore, the noise at the regulator output. Note that the output will
start up slower as the bypass capacitance increases due to the RC time constant at the bypass pin that is created
by the internal 150-kΩ resistor and external capacitor.
Current limiting and thermal protection prevent damage by excessive output current and/or power dissipation.
The device switches into a constant-current mode at approximately 350 mA; further load reduces the output
voltage instead of increasing the output current. The thermal protection shuts the regulator off if the junction
temperature rises above approximately 165°C. Recovery is automatic when the junction temperature drops
approximately 25°C below the high temperature trip point. The PMOS pass element includes a back gate diode
that conducts reverse current when the input voltage level drops below the output voltage level.
A voltage of 1.7 V or greater on the EN input will disable the TPS790xx internal circuitry, reducing the supply
current to 1 µA. A voltage of less than 0.9 V on the EN input will enable the TPS790xx and will enable normal
operation to resume. The EN input does not include any deliberate hysteresis, and it exhibits an actual switching
threshold of approximately 1.5 V.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Ĕ
Input voltage range
(see Note 1)
–0.3 V to 13.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range at EN –0.3 V to VI + 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage on OUT, FB 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Peak output current Internally limited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ESD rating, HBM 2 kV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous total power dissipation See Dissipation Rating Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating virtual junction temperature range, TJ –40°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, Tstg –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only , and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may af fect device reliability.
NOTE 1: All voltage values are with respect to network ground terminal.
DISSIPATION RATING TABLE
BOARD PACKAGE RθJC RθJA DERATING FACTOR
ABOVE TA = 25°CTA ≤ 25°C
POWER RATING TA = 70°C
POWER RATING TA = 85°C
POWER RATING
Low K‡DBV 65.8 °C/W 259 °C/W 3.9 mW/°C386 mW 212 mW 154 mW
High K§DBV 65.8 °C/W 180 °C/W 5.6 mW/°C555 mW 305 mW 222 mW
‡The JEDEC Low K (1s) board design used to derive this data was a 3 inch x 3 inch, two layer board with 2 ounce copper traces on top of the board.
§The JEDEC High K (2s2p) board design used to derive this data was a 3 inch x 3 inch, multilayer board with 1 ounce internal power and ground
planes and 2 ounce copper traces on top and bottom of the board.
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
4POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
recommended operating conditions
MIN NOM MAX UNIT
Input voltage, VI (see Note 2) 2.7 10 V
Continuous output current, IO (see Note 3) 0 50 mA
Operating junction temperature, TJ–40 125 °C
NOTES: 2. To calculate the minimum input voltage for your maximum output current, use the following formula:
VI(min) = VO(max) + VDO (max load)
3. Continuous output current and operating junction temperature are limited by internal protection circuitry , but it is not recommended
that the device operate under conditions beyond those specified in this table for extended periods of time.
electrical characteristics over recommended operating free–air temperature range,
VI = VO(typ) + 1 V, IO = 1 mA, EN = 0V, Co = 4.7 µF (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
TPS79015
TJ = 25°C, 2.7 V < VI < 10 V 1.5
TPS79015
TJ = –40°C to 125°C, 2.7 V < VI < 10 V 1.455 1.545
TPS79018
TJ = 25°C, 2.8 V < VI < 10 V 1.8
TPS79018
TJ = –40°C to 125°C, 2.8 V < VI < 10 V 1.746 1.854
Output volta
g
e (10
µ
A to 50 mA load)
TPS79025
TJ = 25°C, 3.5 V < VI < 10 V 2.5
V
g( µ)
(see Note 4)
TPS79025
TJ = –40°C to 125°C, 3.5 V < VI < 10 V 2.425 2.575
V
TPS79028
TJ = 25°C, 3.8 V < VI < 10 V 2.8
TPS79028
TJ = –40°C to 125°C, 3.8 V < VI < 10 V 2.716 2.884
TPS79030
TJ = 25°C, 4.0 V < VI < 10 V 3
TPS79030
TJ = –40°C to 125°C, 4.0 V < VI < 10 V 2.910 3.090
Quiescent current (GND current) (see Note 4)
EN = 0 V, 10 µA < IO < 50 mA,
TJ = 25°C17
µA
Quiescent
current
(GND
current)
(see
Note
4)
EN = 0 V, IO = 50 mA,
TJ = –40°C to 125°C28 µ
A
Load regulation EN = 0 V, IO = 10 µA to 50 mA,
TJ = 25°C8 mV
Out
p
ut voltage line regulation (∆VO/VO)
VO + 1 V < VI ≤ 10 V, TJ = 25°C 0.04
Output
voltage
line
regulation
(∆V
O
/V
O)
(see Notes 4 and 5) VO + 1 V < VI ≤ 10 V,
TJ = –40°C to 125°C0.1 %/V
Output noise voltage (TPS79030) BW = 300 Hz to 50 kHz, C(byp) = 0.01 µF,
Co = 10 µF, IO = 50 mA, TJ = 25°C56 µVrms
Output current limit VO = 0 V, See Note 4 350 750 mA
Standby current
EN = VI , 2.7 < VI < 10 V 1µA
Standby
current
TJ = –40°C to 125°C 2 µA
NOTES: 4. The minimum IN operating voltage is 2.7 V or VO (typ) + 1 V , whichever is greater. The maximum IN voltage is 10 V . The minimum
output current is 10 µA and the maximum output current is 50 mA.
5. If VO≤ 1.8 V then VImin = 2.7 V, VImax = 10 V:
Line Reg. (mV)
+ǒ
%
ń
V
Ǔ
VO
ǒ
VImax
*
2.7 V
Ǔ
100
1000
If VO≥ 2.5 V then VImin = VO + 1 V, VImax = 10 V:
Line Reg. (mV)
+ǒ
%
ń
V
Ǔ
VO
ǒ
VImax
*ǒ
VO
)
1V
ǓǓ
100
1000
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free–air temperature range,
VI = VO(typ) + 1 V, IO = 1 mA, EN = 0V, Co = 4.7 µF (unless otherwise noted) (continued)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
High level enable input voltage 2.7 V < VI < 10 V 1.7 V
Low level enable input voltage 2.7 V < VI < 10 V 0.9 V
Power supply ripple rejection (TPS79030) f = 1 kHz, Co = 10 µF,
TJ = 25°C, C(byp) = 0.01 µF85 dB
In
p
ut current (EN)
EN = 0 V –1 0 1 µA
Input
current
(EN)
EN = VI–1 1 µA
p
TPS79028
IO = 50 mA, TJ = 25°C 60
TPS79028
IO = 50 mA, TJ = –40°C to 125°C 125
mV
p
TPS79030
IO = 50 mA, TJ = 25°C 57
mV
TPS79030
IO = 50 mA, TJ = –40°C to 125°C115
6. IN voltage equals VO(typ) –100 mV; The TPS79030 output voltage is set to 2.9 V. The TPS79015, TPS79018, and TPS79025
dropout voltage is limited by input voltage range limitations.
TYPICAL CHARACTERISTICS
Table of Graphs
FIGURE
VO
Out
p
ut voltage
vs Output current 1, 2, 3
V
O
Output
voltage
vs Junction temperature 4, 5, 6
Ground current vs Junction temperature 7
Output spectral noise density vs Frequency 8 – 10
Root mean squared output noise vs Bypass capacitance 11
ZoOutput impedance vs Frequency 12
VDO Dropout voltage vs Junction temperature 13
Ripple rejection vs Frequency 14 – 16
VOOutput voltage, enable voltage vs Time (start-up) 17 – 19
Line transient response 20, 22
Load transient response 21, 23
Equivalent series resistance (ESR) vs Output current 24, 25
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
6POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 1
TPS79025
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
2.500
2.485 10 30
2.505
2.495
20 40
2.545
050
– Output Voltage – V
VO
2.510
2.490
IO – Output Current – mA
VI = 3.5 V
Co = 4.7 µF
TJ = 25°C
Figure 2
IO – Output Current – mA
1.495
1.485 10 30
1.505
1.500
1.490
20 40
1.515
050
– Output Voltage – V
VO
TPS79015
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
1.510
VI = 2.7 V
Co = 4.7 µF
TJ = 25°C
Figure 3
2.985
2.990
2.995
3.000
3.005
3.010
3.015
01020304050
IO – Output Current – mA
TPS79030
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
– Output Voltage – V
VO
VI = 4 V
Co = 4.7 µF
TJ = 25°C
Figure 4
TJ – Junction Temperature – °C
TPS79015
OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
1.495
1.485
1.500
1.515
1.510
– Output Voltage – V
VO
1.505
1.490
IO = 1 mA
VI = 2.7 V
Co = 4.7 µF
IO = 50 mA
–40 5–25 20 35 65 110 12550–10 80 95
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 5
TJ – Junction Temperature – °C
TPS79025
OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
2.485
2.510
2.500
2.515
– Output Voltage – V
VO
2.490
IO = 1 mA
IO = 50 mA
VI = 3.5 V
Co = 4.7 µF
2.505
2.495
–40 5–25 20 35 65 110 12550–10 80 95
Figure 6
2.985
2.990
2.995
3.000
3.005
3.010
3.015
–40 –25 –10 5 20 35 50 65 80 95 110 125
IO = 50 mA
IO = 1 mA
TJ – Junction Temperature – °C
TPS79030
OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
– Output Voltage – V
VO
VI = 4 V
Co = 4.7 µF
Figure 7
TJ – Junction Temperature – °C
15
22
TPS79030
GROUND CURRENT
vs
JUNCTION TEMPERATURE
Ground Current – Aµ
VI = 4 V
Co = 4.7 µF
21
20
19
18
17
16
IO = 1 mA
IO = 50 mA
–40 5–25 20 35 65 110 12550–10 80 95
Figure 8
0
200
400
600
800
1000
1200
100 1k 10k 100k
f – Frequency – Hz
VI = 4 V
Co = 4.7 µF
C(byp) = 0.1 µF
TPS79030
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
IO = 1 mA
IO = 50 mA
nV/ HzOutput Spectral Noise Density –
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
8POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
100 1k 10k 100k
f – Frequency – Hz
VI = 4 V
Co = 10 µF
C(byp) = 0.1 µF
TPS79030
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
IO = 50 mA
0
100
200
300
400
500
600
700
IO = 1 mA
nV/ HzOutput Spectral Noise Density –
Figure 9 Figure 10
0
200
400
600
800
1000
1200
1400
1600
1800
100 1k 10k 100k
C(byp) = 0.001 µF
C(byp) = 0.01 µF
C(byp) = 0.1 µF
f – Frequency – Hz
TPS79030
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
nV/ HzOutput Spectral Noise Density –
VI = 4 V
IO = 50 mA
Co = 10 µF
150
100
50
0
0.00001 0.0001 0.001 0.01
RMS – Root Mean Squared Output Noise –
200
250
ROOT MEAN SQUARED OUTPUT NOISE
vs
BYPASS CAPACITANCE
300
0.1 1
(RMS)
Vµ
C(bypass) – Bypass Capacitance – µF
VO = 3 V
VO = 1.5 V
Figure 11
Co = 10 µF
Figure 12
100 1M10 1k
f – Frequency – Hz
10k
– Output Impedance –ZoΩ
OUTPUT IMPEDANCE
vs
FREQUENCY
0
1.6
1
2
0.2
1.4
0.4
1.8
0.6
1.2
0.8
100k
VI = 4 V
Co = 10 µF
TJ = 25°C
IO = 50 mA
IO = 1 mA
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
9
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 13
TA – Junction Temperature – °C
5
45
75
– Dropout Voltage – mV
VDO
TPS79030
DROPOUT VOLTAGE
vs
JUNCTION TEMPERATURE
–40 5–25 20 35 65 110 12550–10 80 95
VI = 2.9 V
Co = 4.7 µF
IO = 50 mA
IO = 1 mA
15
25
35
55
65
Figure 14
20
30
40
50
60
70
80
90
100
110
f – Frequency – Hz
TPS79030
RIPPLE REJECTION
vs
FREQUENCY
VI = 4 V
Co = 4.7 µF
C(byp) = 0.1 µF
IO = 50 mA
IO = 1 mA
1M100k10k1k10010
Ripple Rejection –dB
Figure 15
20
30
40
50
60
70
80
90
100
f – Frequency – Hz
TPS79030
RIPPLE REJECTION
vs
FREQUENCY
VI = 4 V
Co = 4.7 µF
C(byp) = 0.01 µF
IO = 50 mA
IO = 1 mA
1M100k10k1k10010
Ripple Rejection –dB
20
30
40
50
60
70
80
90
100
f – Frequency – Hz
TPS79030
RIPPLE REJECTION
vs
FREQUENCY
VI = 4 V
Co = 4.7 µF
C(byp) = 0.001 µF
IO = 50 mA
IO = 1 mA
1M100k10k1k10010
Ripple Rejection –dB
Figure 16
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 17
VI = 4 V
CO = 4.7 µF
3
TPS79030
OUTPUT VOLTAGE, ENABLE VOLTAGE
vs
TIME (START-UP)
VO
t – Time – ms
032145768910
– Output Voltage – V
VI = 4 V
VO = 3 V
IO = 50 mA
C(byp) = 0.01 µF
Co = 4.7 µF
TJ = 25°C
Enable Voltage – V
1
5
0
0
2
Figure 18
3
TPS79030
OUTPUT VOLTAGE, ENABLE VOLTAGE
vs
TIME (START-UP)
VO
t – Time – ms
0 0.60.40.2 0.8 1 1.41.2 1.6 1.8 2
– Output Voltage – V
VI = 4 V
VO = 3 V
IO = 50 mA
C(byp) = 0.001 µF
Co = 4.7 µF
TJ = 25°C
Enable Voltage – V
1
5
0
0
2
Figure 19
3
TPS79030
OUTPUT VOLTAGE, ENABLE VOLTAGE
vs
TIME (START-UP)
VO
t – Time – ms
0302010 40 50 7060 80 90 100
– Output Voltage – V
VI = 4 V
VO = 3 V
IO = 50 mA
Co = 4.7 µF
TJ = 25°C
Enable Voltage – V
1
5
0
0
2
C(byp) = 0.001 µFC(byp) = 0.1 µF
C(byp) = 0.01 µF
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 20
3.7
TPS79015
LINE TRANSIENT RESPONSE
t – Time – µs
0604020 80 100 140120 160 180 200
IO = 10 mA
Co = 4.7 µF
2.7
20
0
VO – Output Voltage – mVVI– Input Voltage – V
–20
Figure 21
t – Time – µs
TPS79015
LOAD TRANSIENT RESPONSE
0
0
0604020 80 100 140120 160 180 200
Current Load – mA
50
VI = 2.7 V
Co = 10 µF
–50
–100
VO
Output Voltage – mV
∆ – Change In
Figure 22
20
TPS79030
LINE TRANSIENT RESPONSE
VO
t – Time – µs
0604020 80 100 140120 160 180 200
– Output Voltage – mV
IO = 10 mA
Co = 4.7 µF
VI– Input Voltage – V
0
5
4.5
4
–20
Figure 23
t – Time – µs
TPS79030
LOAD TRANSIENT RESPONSE
0
0604020 80 100 140120 160 180
50
0
–50
–100
VO
Output Voltage – mV
∆ – Change In
50
200
– Output Current – mA
IO
VI = 4 V
Co = 4.7 µF
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 24
1
02550
100
IO – Output Current – mA
ESR – Equivalent Series Resistance – Ω
10
TPS79030
TYPICAL REGIONS OF STABILITY
EQUIVALENT SERIES RESISTANCE (ESR)
vs
OUTPUT CURRENT
5 1015 20 30354045
Region of Stability
0.1
VI = 4 V
Co = 4.7 µF
VO = 3 V
Region of Instability
Figure 25
IO – Output Current – mA
102550
100
ESR – Equivalent Series Resistance – Ω
10
TPS79030
TYPICAL REGIONS OF STABILITY
EQUIVALENT SERIES RESISTANCE (ESR)
vs
OUTPUT CURRENT
VI = 4 V
Co = 10 µF
VO = 3 V
5 1015 20 30354045
Region of Stability
Region of Instability
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
13
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
The TPS790xx family of low-dropout (LDO) regulators have been optimized for use in battery-operated
equipment. They feature extremely low dropout voltages, low quiescent current (17 µA typically), and enable
inputs to reduce supply currents to less than 1 µA when the regulators are turned off.
A typical application circuit is shown in Figure 26.
C1
1 µF
BYPASS
OUT
1
3
IN
EN
GND
2
4
5
VI
ESR = 0.2 Ω
VO
4.7 µF
+
TPS790xx†
0.01 µF
Figure 26. Typical Application Circuit
external capacitor requirements
Although not required, a 0.047-µF or larger ceramic input bypass capacitor, connected between IN and GND
and located close to the TPS790xx, is recommended to improve transient response and noise rejection. A
higher-value electrolytic input capacitor may be necessary if large, fast-rise-time load transients are anticipated
and the device is located several inches from the power source.
Like all low dropout regulators, the TPS790xx requires an output capacitor connected between OUT and GND
to stabilize the internal control loop. The minimum recommended capacitance is 4.7 µF. The ESR (equivalent
series resistance) of the capacitor should be between 0.2 Ω and 10 Ω to ensure stability . Capacitor values larger
than 4.7 µF are acceptable, and allow the use of smaller ESR values. Capacitances less than 4.7 µF are not
recommended because they require careful selection of ESR to ensure stability. Solid tantalum electrolytic,
aluminum electrolytic, and multilayer ceramic capacitors are all suitable, provided they meet the requirements
described above. Most of the commercially available 4.7 µF surface-mount solid tantalum capacitors, including
devices from Sprague, Kemet, and Nichico, meet the ESR requirements stated above. Multilayer ceramic
capacitors may have very small equivalent series resistances and may thus require the addition of a low value
series resistor to ensure stability.
CAPACITOR SELECTION
PART NO. MFR. VALUE MAX ESR†SIZE (H × L × W)†
T494B475K016AS KEMET 4.7 µF 1.5 Ω1.9 × 3.5 × 2.8
195D106x0016x2T SPRAGUE 10 µF 1.5 Ω1.3 × 7.0 × 2.7
695D106x003562T SPRAGUE 10 µF 1.3 Ω2.5 × 7.6 × 2.5
TPSC475K035R0600 AVX 4.7 µF 0.6 Ω2.6 × 6.0 × 3.2
†Size is in mm. The ESR maximum resistance is in Ohms at 100 kHz and TA = 25°C. Contact the
manufacturer for the minimum ESR values.
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
external capacitor requirements (continued)
The external bypass capacitor , used in conjunction with an internal resistor to form a low-pass filter, should be
a low ESR ceramic capacitor. For example, the TPS79030 exhibits only 56 µVRMS of output voltage noise using
a 0.01 µF ceramic bypass capacitor and a10 µF ceramic output capacitors. Note that the output will start up
slower as the bypass capacitance increases due to the RC time constant at the bypass pin that is created by
the internal 150 kΩ resistor and external capacitor.
power dissipation and junction temperature
Specified regulator operation is assured to a junction temperature of 125°C; the maximum junction temperature
should be restricted to 125°C under normal operating conditions. This restriction limits the power dissipation
the regulator can handle in any given application. T o ensure the junction temperature is within acceptable limits,
calculate the maximum allowable dissipation, PD(max), and the actual dissipation, PD, which must be less than
or equal to PD(max).
The maximum-power-dissipation limit is determined using the following equation:
PD(max)
+
TJmax
*
TA
R
q
JA
Where:
TJmax is the maximum allowable junction temperature.
RθJA is the thermal resistance junction-to-ambient for the package, see the dissipation rating table.
TA is the ambient temperature.
The regulator dissipation is calculated using:
PD
+ǒ
VI
*
VO
Ǔ
IO
Power dissipation resulting from quiescent current is negligible. Excessive power dissipation will trigger the
thermal protection circuit.
regulator protection
The TPS790xx PMOS-pass transistor has a built-in back diode that conducts reverse current when the input
voltage drops below the output voltage (e.g., during power down). Current is conducted from the output to the
input and is not internally limited. If extended reverse voltage operation is anticipated, external limiting might
be appropriate.
The TPS790xx features internal current limiting and thermal protection. During normal operation, the TPS790xx
limits output current to approximately 350 mA. When current limiting engages, the output voltage scales back
linearly until the overcurrent condition ends. While current limiting is designed to prevent gross device failure,
care should be taken not to exceed the power dissipation ratings of the package. If the temperature of the device
exceeds approximately 165°C, thermal-protection circuitry shuts it down. Once the device has cooled down to
below approximately 140°C, regulator operation resumes.
TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
MECHANICAL DATA
DBV (R-PDSO-G5) PLASTIC SMALL-OUTLINE
0,10
M
0,20
0,95
0°–8°
0,25
0,35
0,55
Gage Plane
0,15 NOM
4073253-4/F 10/00
2,60
3,00
0,50
0,30
1,50
1,70
45
31
2,80
3,00
0,95
1,45 0,05 MIN
Seating Plane
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion.
D. Falls within JEDEC MO-178
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