MIC5303
Single 300mA CMOS
Ultra Small ULDO™
ULDO is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
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 2008 M9999-051508-D
General Description
The MIC5303 is an ultra small, Ultra Low Dropout CMOS
regulator, ULDO™ that is ideal for today’s most demand-
ing portable applications including cellular phone RF
power, camera modules, imaging sensors for digital still
and video cameras, PDAs, portable media players (PMP)
and PC cameras where board space is limited. It offers
extremely low dropout voltage, very low output noise and
can operate from a 2.3V to 5.5V input while delivering up
to 300mA.
It offers 2% initial accuracy, low ground current (typically
85µA total), thermal and current limit protection. The
MIC5303 can also be put into a zero-off-mode current
state, drawing no current when disabled.
The MIC5303 is available in the ultra small 4-pin 1.2mm x
1.6mm Thin MLF
®
package, occupying only 1.92mm
2
of
PCB area, a 50% reduction in board area compared to
SC-70 and 2mm x 2mm MLF
®
packages. It’s operating
junction temperature range is –40°C to +125°C and is
available in fixed output voltages in lead-free (RoHS
compliant) Thin MLF
®
package.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Features
• Ultra Small 1.2mm x 1.6mm Thin MLF
®
package
• Low Dropout Voltage: 100mV at 300mA
• Output noise 120µVrms
• Input voltage range: 2.3V to 5.5V
• 300mA guaranteed output current
• Stable with ceramic output capacitors
• Low quiescent current 85µA total
• 35µs turn-on time
• High output accuracy
– ±2% initial accuracy
– ±3% over temperature
• Thermal shutdown and current limit protection
Applications
• Mobile Phones
• PDAs
• GPS Receivers
• Portable Media Players
• Portable Electronics
• Digital Still & Video Cameras
Typical Application
VOUTVIN
EN
GND
1µF
1µF
MIC5303-x.xYMT
RF LDO Application
25
50
75
100
125
150
0 100 150 200 250 300
OUTPUT CURRENT (mA)
Dropout Voltage
vs. Output Current
V
OUT
= 2.8V
C
OUT
= 1µF
0
05
Micrel, Inc. MIC5303
May 2008 2 M9999-051508-D
Block Diagram
V
IN
EN
VOUT
GND
Current
Limit
LDO
Quick-
Start
V
REF
Thermal
Shutdown
Error
Amp
MIC5303 Block Diagram
Micrel, Inc. MIC5303
May 2008 3 M9999-051508-D
Ordering Information(1)
Part Number Marking Code Voltage Temperature Range Package Lead Finish
MIC5303-1.5YMT 1M5 1.5V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-1.8YMT 1M8 1.8V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-2.1YMT 2M1 2.1V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-2.5YMT 2M5 2.5V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-2.6YMT 2M6 2.6V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-2.8YMT 2M8 2.8V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-2.85YMT 2MN 2.85V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-2.9YMT 2M9 2.9V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-3.0YMT 3M0 3.0V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
MIC5303-3.3YMT 3M3 3.3V –40°C to +125°C 4-Pin 1.2mm x 1.6mm Thin MLF
®
Pb-Free
Note:
1. Other voltages available. Contact Micrel Marketing for details.
Pin Configuration
1
2
4
3
VOUT
VIN
EN
GND
4-Pin 1.2mm x 1.6mm Thin MLF
®
(MT)
Pin Description
Pin Number Pin Name Pin Function
1 EN Enable Input. Active High. High = on, low = off. Do not leave floating.
2 GND Ground
3 VIN Supply Input
4 VOUT Output Voltage
HS Pad EPAD Exposed heatsink pad connected to ground internally.
Micrel, Inc. MIC5303
May 2008 4 M9999-051508-D
Absolute Maximum Ratings(1)
Supply Voltage (V
IN
)............................................. 0V to +6V
Enable Input (V
EN
) ................................................ 0V to +6V
Power Dissipation
(3)
...................................Internally Limited
Lead Temperature (soldering, 5 sec.)........................ 260°C
Junction Temperature (T
J
) ........................–40°C to +125°C
Storage Temperature (T
s
) .........................–65°C to +150°C
Operating Ratings(2)
Supply voltage (V
IN
) ..................................... +2.3V to +5.5V
Enable Input (V
EN
) .................................................. 0V to V
IN
Junction Temperature (T
A
) ........................ –40°C to +125°C
Junction Thermal Resistance
Thin MLF
®
-4 (θ
JA
) ...........................................173°C/W
Electrical Characteristics(4)
V
IN
= V
OUT
+ 1V; C
OUT
= 1.0µF; I
OUT
= 100µA; T
J
= 25°C, bold values indicate –40°C to +125°C, unless noted.
Parameter Condition Min Typ Max Units
Variation from nominal V
OUT
–2 +2 % Output Voltage Accuracy
Variation from nominal V
OUT
; –40°C to +125°C –3 +3 %
Line Regulation V
IN
= V
OUT
+1V to 5.5V; I
OUT
= 100µA 0.02 0.3
0.6
%/V
Load Regulation
(5)
I
OUT
= 100µA to 150mA 0.5 2.0 %
Dropout Voltage
(6)
I
OUT
= 100µA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 300mA
0.1
15
50
100
35
100
200
mV
mV
mV
mV
Ground Pin Current
(7)
I
OUT
= 0 to 300mA, EN = High 85 120 µA
Ground Pin Current in
Shutdown
V
EN
= 0V 0.1 2 µA
Ripple Rejection f = up to 1kHz; C
OUT
= 1.0µF
f = 1kHz – 20kHz; C
OUT
= 1.0µF
65
42
dB
dB
Current Limit V
OUT
= 0V 350 460 850 mA
Output Voltage Noise C
OUT
=1µF, 10Hz to 100kHz 120 µV
RMS
Enable Input
Logic Low 0.2 V Enable Input Voltage
Logic High 1.1 V
V
IL
< 0.2V 0.01 µA Enable Input Current
V
IH
> 1.0V 0.01 µA
Turn-on Time C
OUT
= 1.0µF 35 100 µs
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. The maximum allowable power dissipation of any T
A
(ambient temperature) is P
D(max)
= (T
J(max)
- T
A
) / θ
JA
. Exceeding the maximum allowable power
dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown.
4. Specification for packaged product only.
5. Regulation is measured at constant junction temperature using low duty cycle pulse testing, changes in output voltage due to heating effects are
covered by the thermal regulation specification.
6. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value measured at 1V differential.
7. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground pin
current.
Micrel, Inc. MIC5303
May 2008 5 M9999-051508-D
Typical Characteristics
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250 300
OUTPUT CURRENT (mA)
Ground Pin Current
vs. Output Current
C
OUT
= 1µF
V
OUT
= 2.8V
V
IN
= V
OUT
+ 1V
70
72
80
82
84
86
88
90
Ground Pin Current
vs. Temperature
20 40 60 80
TEMPERATURE (°C)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
100µA
300mA
74
76
78
0
10
20
30
40
50
60
70
80
90
100
3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
Ground Pin Current
vs. Supply Voltage
100µA
300mA
0
-10
-20
-30
-40
-50
-60
-70
-80
Power Supply
Rejection Ratio
FREQUENCY (kHz)
10.1 10 100 1,000
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
50mA
150mA
300mA
100
120
140
160
Dropout Voltage
vs. Temperature
20 40 60 80
TEMPERATURE (°C)
VOUT = 2.8V
COUT = 1µF
100µA
50mA
300mA
150mA
0
20
40
60
80
0
25
50
75
100
125
150
0 100 150 200 250 300
OUTPUT CURRENT (mA)
Dropout Voltage
vs. Output Current
V
OUT
= 2.8V
C
OUT
= 1µF
0
05
2.77
2.78
2.79
2.80
2.81
2.82
2.83
0 50 100 150 200 250 300
OUTPUT CURRENT (mA)
Output Voltage
vs. Output Current
COUT = 1µF
VOUT = 2.8V
VIN = VOUT + 1V
0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
0123456
SUPPLY VOLTAGE (V)
Output Voltage
vs. Supply Voltage
100µA
COUT = 1µF
300mA
2.50
2.55
2.60
2.65
2.70
2.85
2.90
2.95
3.00
Output Voltage
vs. Temperature
20 40 60 80
TEMPERATURE (°C)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
I
OUT
= 100µA
2.75
2.80
400
410
420
430
440
450
460
470
480
490
500
3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE (V)
Current Limit
vs. Input Voltage
VOUT = 2.8V
COUT = 1µF
0.001
0.01
0.1
1
10
Output Noise
Spectral Density
1
FREQUENCY (kHz)
0.10.01 10 100 1,000
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
Micrel, Inc. MIC5303
May 2008 6 M9999-051508-D
Functional Characteristics
Enable Turn-On
Enable
(1V/div)
Output Volta
g
e
(1V/div)
Time (10µs/div)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
Load Transient Response
Output Volta
g
e
(50mV/div)
Output Current
(100mA/div)
Time (40µs/div)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
300mA
Line Transient Response
Input Volta
g
e
(2V/div)
Output Voltage
(50mV/div)
Time (40µs/div)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
I
OUT
= 10mA
5V
4V
Micrel, Inc. MIC5303
May 2008 7 M9999-051508-D
Application Information
Enable/Shutdown
The MIC5303 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 a “zero”
off-mode-current state. In this state, current consumed
by the regulator goes nearly to zero. Forcing the enable
pin high enables the output voltage. The active-high
enable pin uses CMOS technology and the enable pin
cannot be left floating; a floating enable pin may cause
an indeterminate state on the output.
Input Capacitor
The MIC5303 is a high-performance, high bandwidth
device. Therefore, it requires a well-bypassed input
supply for optimal performance. A 1µF capacitor is
required from the input-to-ground to provide stability.
Low-ESR ceramic capacitors provide optimal perfor-
mance 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.
Output Capacitor
The MIC5303 requires an output capacitor of 1µF or
greater to maintain stability. The design is optimized for
use with low-ESR ceramic chip capacitors. High ESR
capacitors may cause high frequency oscillation. The
output capacitor can be increased, but performance has
been optimized for a 1µF 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 most stable type of ceramic capacitors. Z5U and
Y5V 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 MIC5303 will
remain stable and in regulation with no load. This is
especially important in CMOS RAM keep-alive
applications.
Thermal Considerations
The MIC5303 is designed to provide 300mA of
continuous current. Maximum ambient operating
temperature can be calculated based on the output
current and the voltage drop across the part. Given that
the input voltage is 3.6V, the output voltage is 2.8V and
the output current = 300mA.
The actual power dissipation of the regulator circuit can
be determined using the equation:
P
D
= (V
IN
– V
OUT
) I
OUT
+ V
IN
I
GND
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 for this calculation.
P
D
= (3.6V – 2.8V) × 300mA
P
D
= 0.24W
To determine the maximum ambient operating
temperature of the package, use the junction-to-ambient
thermal resistance of the device and the following basic
equation:
P
D(MAX)
=
T
J(MAX)
- T
A
JA
⎝
⎛
T
J(max)
= 125°C, the maximum junction temperature of
the die θ
JA
thermal resistance = 173°C/W.
The table below shows junction-to-ambient thermal
resistance for the MIC5303 in the 4-pin 1.2mm x 1.6mm
MLF
®
package.
Package θ
JA
Recommended
Minimum Footprint
4-Pin 1.2x1.6 MLF
®
173°C/W
Thermal Resistance
Substituting P
D
for P
D(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 example, when operating the MIC5303-2.8YML at
an input voltage of 3.6V and 300mA load with a
minimum footprint layout, the maximum ambient
operating temperature T
A
can be determined as follows:
0.24W = (125°C – T
A
)/(173°C/W)
T
A
=83°C
Therefore, a 2.8V application with 300mA of output
current can accept an ambient operating temperature of
83°C in a 1.2mm x 1.6mm MLF
®
package. For a full
discussion of heat sinking 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
Micrel, Inc. MIC5303
May 2008 8
M9999-051508-D
Package Information
4-Pin 1.2mm x 1.6mm Thin MLF
®
(MT)
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
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
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 life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2006 Micrel, Incorporated.
