MIC5528
High-Performan ce 50 0mA LDO
in Thin and Extra Thin DFN Packages
General Description
The MIC5528 is a low-power, µCap, low dropout regulator
designed f or optimal per formance in a ver y-small foot print .
It is capable of sourcing up to 500mA of output current
while only drawing 38µA of operating current. This high-
performance LDO is a µCap design in a thermally
enhanced 1.2mm × 1.2mm extra thin (0.4mm ht.) DFN
package. It operates with small ceramic output capacitor
for stability, thereby reducing required board space.
Ideal for battery-operat ed applicati ons, the MIC5528 offers
±2% accuracy, extremely low dropout voltage (260mV @
500mA), and can regulate output voltages down to 1.0V.
Equipped with a TTL logic-compatible enable pin, the
MIC5528 can be put into a zero-off-mode current state,
drawing no current when disabled.
The MIC5528 is a µCap design, operating with very small
ceramic output capacitors for stability, reducing required
board space and component cost for space-critical
applications. The MIC5528 has an operating junction
temperature range of –40°C to 125°C.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
• Input voltage range: 2.5V to 5.5V
• Fixed output voltages down to 1.0V
• ±2% Room temperature accuracy
• Low quiescent current 38µA
• Stable with 2.2µF ceramic output capacitors
• Low dropout voltage 260mV @ 500mA
• Auto discharge and internal enable pulldown
• Thermal-shutdown and current-limit protection
• 6-pin 1.2mm × 1.2mm extra thin DFN package
• 6-pin 1.2mm × 1.2mm thin DFN package
Applications
• Portable communication equipment
• DSC, GPS, PMP, and PDAs
• Portable medical devices
• 5V POL applications
Typical Ap plication
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
May 5, 2014 Revision 1.1
Micrel, Inc.
MIC5528
Ordering Information
Part Number Marking
Code Output
Voltage(1) Auto-
Discharge EN
Pulldown Temperature
Range Package(2, 3, 4)
MIC5528-3.3YMT CF 3.3V YES YES –40°C to +125°C 6-Pin 1.2mm × 1.2mm TDFN
MIC5528-2.8YMX CI 2.8V YES YES –40°C to +125°C 6-Pin 1.2mm × 1.2mm XTDFN
MIC5528-3.3YMX CF 3.3V YES YES –40°C to +125°C 6-Pin 1.2mm × 1.2mm XTDFN
Notes:
1. Other volt ages avail abl e. Contact Micrel for details.
2. Thin DF N ▲ = Pin 1 identifier.
3. Extra Thin DFN ▼ = Pin 1 identifier.
4. Extra Thin and Thin DFN are GREEN, RoHS-compliant packages. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configuration
6-Pin 1.2mm × 1.2mm Thin DFN (MT)
(Top View)
6-Pin 1.2mm × 1.2mm Extra Thin DFN (MX)
(Top View)
Pin Description
Pin Number Pin Name
XTDFN-6 Pin Function
1, 2 VOUT Output Voltage. When disabled the MIC5528 switches in an internal 25Ω load to discharge the
external capacitors.
3 GND Ground.
4 EN Enable Input: Active High. High = ON; Low = OFF. The MIC5528 has an internal pulldown and
this pin can be left floating.
5 NC No Connection.
6 VIN Supply Input.
EP ePad Exposed Heatsink Pad. Connect to GND for best thermal performance.
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Micrel, Inc.
MIC5528
Absolute Maximum Ratings(5)
Supply Voltage (VIN) .......................................... –0.3V to 6V
Enable Voltage (VEN). ........................................ –0.3V to VIN
Power Dissipation (PD) ........................... Interna lly Limited(7)
Lead Temperature (soldering, 10sec) ........................ 260°C
Junction Temperature (TJ) ........................ –40°C to +150°C
Storage Temperature (Ts) ......................... –65°C to +150°C
ESD Rating(8) .................................................................. 3kV
Operating Ratings(6)
Supply Voltage (VIN) ......................................... 2.5V to 5.5V
Enable Voltage (VEN) .............................................. 0V to VIN
Junction Temperature (TJ) ........................ –40°C to +125°C
Junction Thermal Resistance
1.2mm × 1.2mm Extra Thin DFN-6 (θJA) ......... 173°C/W
Electrical Characteristics(9)
VIN = VEN = VOUT + 1V; CIN = COUT = 2.2µF; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C to +85°C, unless note d.
Parameter Condition Min. Typ. Max. Units
Output Voltage Accuracy Variation from nominal VOUT –2.0 ±1 +2.0 %
Variation from nominal VOUT; –40°C to +85°C
–3.0
+3.0
Line Regulation VIN = VOUT +1V to 5.5V; IOUT = 100µA 0.02 0.3 %/V
Load Regulation
(10)
IOUT = 100µA to 500mA 14 65 mV
Dropout Voltage(11) IOUT = 150mA
IOUT = 500mA 80
260 180
500
mV
Ground Pin Current(12) IOUT = 0mA
IOUT = 500mA 38
42 55
65 µA
Ground Pin Current in Shutdown VEN = 0V 0.05 1 µA
Ripple Rejection f = 100Hz, IOUT = 100mA 70 dB
f = 1kHz, IOUT = 100mA 60 dB
Current Limit VOUT = 0V 525 800 mA
Output Voltage Noise f =10Hz to 100kHz 175 µVRMS
Auto-Discharge NFET Resistance VEN = 0V; VIN = 3.6V ; IOUT = –3mA 25 Ω
Enable Input
Enable Pulldown Resistor 4
MΩ
Enable Input Voltage Logic Low 0.2 V
Logic High 1.2
Enable Input Current
VEN = 0V 0.01 1 µA
VEN = 5.5V 1.4 2
Turn-On Time IOUT = 150mA 50 125 µs
Notes:
5. Exceeding the absolute maximum rating can damage the device.
6. The device is not guarant eed to function outside its operat i ng rating.
7. The maximum allowable power dissi pation of any TA (ambient temperature) is PD(max) = (TJ(max) – TA) / θJA. Exceeding the maximum allowable power
dissipati on will resul t in excessi ve die tem perat ure, and the regulat or will go into thermal shutdown.
8. Devices are ESD sens iti ve. Handl ing precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
9. Specific at i on for pack aged product only.
10. Regulation is m easured at constant j unct i on temperature using low duty cycle pulse testing. Changes in output voltage due to heating effects are
covered by the thermal regulation spec ification.
11. Dropout voltage is defined as t he input-to-output differential at which the output volt age drops 2% below its nominal value measured at 1V
different i al. For outputs below 2.5V, dropout voltage is the input-to-output differential with the minimum input voltage 2.5V.
12. Ground pin current is t he regulator quiescent c urrent. T he tot al current drawn from the suppl y is the sum of the load current plus the ground pin
current.
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Micrel, Inc.
MIC5528
Typical Characteristics
0
20
40
60
80
100
120
140
160
180
200
220
240
260
050 100 150 200 250 300 350 400 450 500
DROPOUT VOLTAGE (mV)
OUTPUT CURRENT (mA)
Dropout Voltage vs.
Output Curre nt
VOUT = 3.3V
CIN = COUT = 2.2µF
0
50
100
150
200
250
300
350
-40 -20 020 40 60 80
DROPOUT VOLTAGE (mV)
TEMPERATURE (°C)
Dropout Voltage
vs.Temperature
50mA
300mA
500mA
VOUT = 3.3V
CIN = COUT = 2.2µF
20
25
30
35
40
45
50
55
2.5 33.5 44.5 55.5
GROUND CURRENT (µA)
SUPPLY VOLTAGE (V)
Ground Current
vs. Supply Voltage
500mA
100µA
V
EN
= V
IN
V
OUT
= 3.3V
C
IN
= C
OUT
= 2.2µF
36
37
38
39
40
41
42
43
44
45
46
050 100 150 200 250 300 350 400 450 500
GROUND CURRENT (µA)
LOAD CURRENT (mA)
Ground Current
vs. Load Current
V
IN
= V
EN
= V
OUT
+ 1
V
OUT
= 3.3V
C
IN
= C
OUT
= 2.2µF
30
32
34
36
38
40
42
44
46
48
50
-40 -20 020 40 60 80
GROUND CURRENT (µA)
TEMPERATURE (°C)
Ground Current
vs. Temperatur e
100µA
300mA
500mA
VIN = VEN = VOUT + 1V
VOUT = 3.3V
CIN = COUT = 2.2µF
3.10
3.15
3.20
3.25
3.30
3.35
3.40
3.45
3.50
0100 200 300 400 500
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
Output Voltage
vs. Output Current
V
IN
= V
EN
= V
OUT
+ 1V
V
OUT
= 3.3V
C
IN
= C
OUT
= 2.2µF
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
2.5 3.0 3.5 4.0 4.5 5.0 5.5
OUTPUT VOLTAGE (V)
SUPPLY VOLTAGE (V)
Output Voltage
vs.Supply Volt age
V
IN
= V
EN
= V
OUT
+ 1
V
OUT
= 3.3V
C
IN
= C
OUT
= 2.2µF
500mA
300mA
50mA
3.2
3.25
3.3
3.35
3.4
3.45
3.5
-40 -20 020 40 60 80
OUTPUT VOLTAGE (V)
TEMPERATURE (°C)
Output Voltage
vs.Temperature
300mA
VIN = VOUT + 1V
VOUT = 3.3V
CIN =COUT = 2.2µF
May 5, 2014 4 Revision 1.1
Micrel, Inc.
MIC5528
Typical Characteristics (Continued)
300
350
400
450
500
550
600
650
700
750
2.5 33.5 44.5 55.5
CURRENT LIMIT (mA)
SUPPLY VOLTAGE (V)
Current Limit
vs. Supply Voltage
V
OUT
=3.3V
CIN = COUT = 2.2µF
0.001
0.01
0.1
1
10
NOISE µV/√Hz
FREQUENCY (Hz)
Output Noise Spectral Density
(MIC5528-3.3YMT)
V
IN
= V
EN1
= 4.5V
C
OUT
= 2.2µF
V
OUT
= 3.3V
10 100 1K 10K 100K 1M 10M
May 5, 2014 5 Revision 1.1
Micrel, Inc.
MIC5528
Functional Characteristics
May 5, 2014 6 Revision 1.1
Micrel, Inc.
MIC5528
Functional Block Diagram
May 5, 2014 7 Revision 1.1
Micrel, Inc.
MIC5528
Application Information
The MIC5528 is a high-performance, low-power 500mA
LDO. The MIC5528 includes an auto-discharge circuit
that is s witc he d on whe n th e r egu lat or is d is abled through
the enable pin. The MIC5528 also offers an internal
pulldown resistor on the enable pin to ensure the output
is disable d if the contr ol signal is tr i-stated. The MIC5528
regulator is fully protected from damage due to fault
conditions, offering linear current limiting and thermal
shutdown.
Input Capacitor
The MIC5528 is a high-performance, high-bandwidth
device. An input capacitor of 2.2µF is required from the
input to ground to provide stability. Low-ESR ceramic
capacitors provide optimal performance at a minimum of
space. Additional high-frequency capacitors, such as
small-valued NPO dielectric-type capacitors, help filter
out high-frequency noise and are good practice in any
RF-based circuit. X5R or X7R dielectrics are
recommended for the input capacitor. Y5V dielectrics
lose most of their capacitance over temperature and are
therefore, not recommended.
Output Capacitor
The MIC5528 requires an output capacitor of 2.2µF or
greater to maintain stability. The design is optimized for
use with low-ESR ceramic chip capacitors. High-ESR
capacitors are not recommended because they may
cause high-frequency oscillation. The output capacitor
can be increased, but performance has been optimized
for a 2.2µF ceramic output capacitor and does not
improve significantly with larger capacitance.
X7R/X5R dielectric-type ceramic capacitors are
recommended because of their temperature
performance. X7R-type capacitors change capacitance
by 15% over their operating temperature range and are
the m ost stable t ype of cer amic capacitors. Z 5U and Y5 V
dielectric capacitors change value by as much as 50%
and 60%, respectively, over their operating temperature
ranges. To use a ceramic chip capacitor with Y5V
dielectric, the value must be much higher than an X7R
ceramic capacitor to ensure the same minimum
capacitance over the equivalent operating temperature
range.
No-Load Stability
Unlike many other voltage regulators, the MIC5528
remains stable and in regulation with no load. This is
especially important in CMOS RAM keep-alive
applications.
Enable/Shutdown
The MIC5528 comes with an active-high enable pin that
allows the regulator to be disabled. Forcing the enable
pin low disables the regulator and sends it into an off
mode current state drawing virtually zero current. When
disabled the MIC5528 switches an internal 25Ω load on
the regulator output to discharge the external capacitor.
Forcing the enable pin high enables the output voltage.
The MIC5528 has an internal pull down resistor on the
enable pin to disable the output when the enable pin is
floating.
Thermal Considerations
The MIC5528 is designed to provide 500mA of
continuous current in a very small package. Maximum
ambient operating temperature can be calculated based
on the output current and the voltage drop across the
part. For example if the input voltage is 3.6V, the output
voltage is 3.3V, and the output current = 500mA. The
actual power dissipation of the regulator circuit can be
determined using Equation 1:
PD = (VIN − VOUT)IOUT + VIN IGND Eq. 1
Because this device is CMOS and the ground current is
typically <100µA over the load range, the power
dissipation contributed by the ground current is <1% and
can be ignored Equation 2:
( )
W150.0P mA500V3.3V6.3
P
D
D=
×−=
Eq. 2
To determine the maximum ambient operating
temperature of the package, use the junction-to-ambient
thermal resistance of the device Equation 3:
θ
−
=
JA
A)MAX(J
)MAX(D
TT
P
Eq. 3
TJ(MAX) = 1 25°C, the m axim um junc tion tem perature of the
die, θJA thermal resistance = 173°C/W for the XTDFN
package.
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Micrel, Inc.
MIC5528
Substituting PD for PD(max) and solving for the ambient
operating temperature will give the maximum operating
conditions for the regulator circuit. The junction-to-
ambient thermal resistance for the minimum footprint is
173°C/W.
The maximum power dissipation must not be exceeded
for proper operation.
For exam ple, when oper ating the MIC55 28-3.3YMX at an
input voltage of 3.6V and a 500mA load with a minimum
footprint layout, the maximum ambient operating
temperature TA can be determined as in Equation 4:
( ) ( )
C99T W
/
C173
/TC125W15.0
A
A
°=
°−°=
Eq. 4
Therefore, the maximum ambient operating temperature
allowed in a ther m ally enhanc ed 1.2mm × 1.2mm XTDFN
package is 99°C. F or a ful l disc ussion of heat s inking and
thermal effects on voltage regulators, refer to the
“Regulator Thermals” section of Micrel’s Designing with
Low-Dropout Voltage Regulators handbook. This
information can be found on Micrel's website at:
http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
May 5, 2014 9 Revision 1.1
Micrel, Inc.
MIC5528
Typical Ap plication Schematic
Bill of Materials
Item Part Number Manufacturer Description Qty.
C1, C2 GRM188R71A225KE15D Murata
(13)
Capacitor, 2.2µF Ceramic, 10V, X5R, Size 0603 2
U1 MIC5528-xxYMT Micrel, Inc.(14) High-Performance 500mA LDO in Thin and Extra Thin
DFN Packages 1
MIC5528-xxYMX
Notes:
13. Murata: www.murata.com.
14. Micrel, Inc.: www.micrel.com.
May 5, 2014 10 Revision 1.1
Micrel, Inc.
MIC5528
PCB Layout Recommendations
Top Layer
Bottom Layer
May 5, 2014 11 Revision 1.1
Micrel, Inc.
MIC5528
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel makes no represent ations or warranties with respec t t o the accuracy or completeness of the information furnis hed in this data sheet. This
informat i on is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specificat i ons and descript i ons at any time without notice. No license, whether express , im plied, aris i ng by estoppel or otherwise, t o any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and condit i ons of sale for such products, Micrel assum es no liabil ity
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liabil ity or warranties
relating to fitness for a partic ular purpose, merchant abi lit y, or inf ri ngem ent of any patent, copyright or other int el lectual property right.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical
implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a
significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in lif e support appliances, devi
ces or systems is a Purchaser’s own risk and Purchaser agrees to fully
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© 2013 Micrel, Incorporated.
May 5, 2014 14 Revision 1.1
