MIC5320
Dual, High Performance 150mA µCap ULDO™
ULDO is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technologies, 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
July 2006
M9999-073106
General Description
The MIC5320 is a tiny Dual Ultra Low-Dropout
(ULDO™) linear regulator ideally suited for portable
electronics. It is ideal for general purpose/ digital
applications which require high power supply ripple
rejection (PSRR) >65dB, eliminating the need for a
bypass capacitor and providing two enable pins for
maximum flexibility. The MIC5320 integrates two high-
performance; 150mA ULDOs into a tiny 6-pin 1.6mm x
1.6mm leadless MLF
®
package, which provides
exceptional thermal package characteristics.
The MIC5320 is a µCap design which enables
operation with very small ceramic output capacitors
for stability, thereby reducing required board space
and component cost. The combination of extremely
low-drop-out voltage, high power supply rejection and
exceptional thermal package characteristics makes it
ideal for powering cellular phone camera modules,
imaging sensors for digital still cameras, PDAs, MP3
players and WebCam applications.
The MIC5320 ULDO™ is available in fixed-output
voltages in the tiny 6-pin 1.6mm x 1.6mm leadless
MLF
®
package which is only 2.56mm
2
in area, less
than 30% the area of the SOT-23, TSOP and MLF
®
3x3 packages. It’s also available in the thin SOT-23-6
lead package. Additional voltage options are
available. For more information, contact Micrel
marketing department.
Data sheets and supporting documentation can be
found on Micrel’s web site at www.micrel.com.
Features
• 2.3V to 5.5V input voltage range
• Ultra-low dropout voltage ULDO™ 35mV @
150mA
• Tiny 6-pin 1.6mm x 1.6mm MLF
®
leadless
package
• Low cost TSOT-23-6 package
• Independent enable pins
• PSRR – >65dB on each LDO
• 150mA output current per LDO
• µCap stable with 1µF ceramic capacitor
• Low quiescent current – 85µA per output
• Fast turn-on time – 30µs
• Thermal shutdown protection
• Current limit protection
Applications
• Mobile phones
• PDAs
• GPS receivers
• Portable electronics
• Portable media players
• Digital still and video cameras
Typical Application
VIN
EN 2
VOUT 1
VOUT 2
GND
MIC5320-x.xYML
1µF
EN 1
1µF
Rx/Synth
Tx
RF
Transceiver
1µF
RF Power Supply Circuit
Micrel, Inc. MIC5320
July 2006
2 M9999-073106
Ordering Information
Part number Manufacturing
Part Number
Voltage Junction Temperature
Range
Package
MIC5320-1.8/1.5YML MIC5320-GFYML 1.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-1.8/1.6YML MIC5320-GWYML 1.8V/1.6V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.5/1.8YML MIC5320-JGYML 2.5V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.5/2.5YML MIC5320-JJYML 2.5V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.6/1.85YML MIC5320-KDYML 2.6V/1.85 –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.6/1.8YML MIC5320-KGYML 2.6V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.7/2.7YML MIC5320-LLYML 2.7V/2.7V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.8/1.5YML MIC5320-MFYML 2.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.8/1.8YML MIC5320-MGYML 2.8V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.8/2.6YML MIC5320-MKYML 2.8V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.8/2.8YML MIC5320-MMYML 2.8V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.8/2.85YML MIC5320-MNYML 2.8V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.85/1.85YML MIC5320-NDYML 2.85V/1.85V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.85/2.6YML MIC5320-NKYML 2.85V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.85/2.85YML MIC5320-NNYML 2.85V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.9/1.5YML MIC5320-OFYML 2.9V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.9/1.8YML MIC5320-OGYML 2.9V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-2.9/2.9YML MIC5320-OOYML 2.9V/2.9V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.0/1.8YML MIC5320-PGYML 3.0V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.0/2.5YML MIC5320-PJYML 3.0V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.0/2.6YML MIC5320-PKYML 3.0V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.0/2.8YML MIC5320-PMYML 3.0V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.0/2.85YML MIC5320-PNYML 3.0V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.0/3.0YML MIC5320-PPYML 3.0V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/1.5YML MIC5320-SFYML 3.3V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/1.8YML MIC5320-SGYML 3.3V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/2.5YML MIC5320-SJYML 3.3V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/2.6YML MIC5320-SKYML 3.3V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/2.7YML MIC5320-SLYML 3.3V/2.7V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/2.8YML MIC5320-SMYML 3.3V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/2.85YML MIC5320-SNYML 3.3V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/2.9YML MIC5320-SOYML 3.3V/2.9V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/3.0YML MIC5320-SPYML 3.3V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/3.2YML MIC5320-SRYML 3.3V/3.2V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-3.3/3.3YML MIC5320-SSYML 3.3V/3.3V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5320-1.8/1.5YD6 MIC5320-GFYD6 1.8V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-1.8/1.6YD6 MIC5320-GWYD6 1.8V/1.6V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.5/1.8YD6 MIC5320-JGYD6 2.5V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.5/2.5YD6 MIC5320-JJYD6 2.5V/2.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.6/1.85YD6 MIC5320-KDYD6 2.6V/1.85 –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.6/1.8YD6 MIC5320-KGYD6 2.6V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.7/2.7YD6 MIC5320-LLYD6 2.7V/2.7V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.8/1.5YD6 MIC5320-MFYD6 2.8V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.8/1.8YD6 MIC5320-MGYD6 2.8V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.8/2.6YD6 MIC5320-MKYD6 2.8V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.8/2.8YD6 MIC5320-MMYD6 2.8V/2.8V –40°C to +125°C 6-Pin TSOT-23
Micrel, Inc. MIC5320
July 2006
3 M9999-073106
MIC5320-2.8/2.85YD6 MIC5320-MNYD6 2.8V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.85/1.85YD6 MIC5320-NDYD6 2.85V/1.85V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.85/2.6YD6 MIC5320-NKYD6 2.85V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.85/2.85YD6 MIC5320-NNYD6 2.85V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.9/1.5YD6 MIC5320-OFYD6 2.9V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.9/1.8YD6 MIC5320-OGYD6 2.9V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-2.9/2.9YD6 MIC5320-OOYD6 2.9V/2.9V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.0/1.8YD6 MIC5320-PGYD6 3.0V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.0/2.5YD6 MIC5320-PJYD6 3.0V/2.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.0/2.6YD6 MIC5320-PKYD6 3.0V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.0/2.8YD6 MIC5320-PMYD6 3.0V/2.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.0/2.85YD6 MIC5320-PNYD6 3.0V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.0/3.0YD6 MIC5320-PPYD6 3.0V/3.0V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/1.5YD6 MIC5320-SFYD6 3.3V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/1.8YD6 MIC5320-SGYD6 3.3V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/2.5YD6 MIC5320-SJYD6 3.3V/2.5V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/2.6YD6 MIC5320-SKYD6 3.3V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/2.7YD6 MIC5320-SLYD6 3.3V/2.7V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/2.8YD6 MIC5320-SMYD6 3.3V/2.8V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/2.85YD6 MIC5320-SNYD6 3.3V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/2.9YD6 MIC5320-SOYD6 3.3V/2.9V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/3.0YD6 MIC5320-SPYD6 3.3V/3.0V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/3.2YD6 MIC5320-SRYD6 3.3V/3.2V –40°C to +125°C 6-Pin TSOT-23
MIC5320-3.3/3.3YD6 MIC5320-SSYD6 3.3V/3.3V –40°C to +125°C 6-Pin TSOT-23
Note:
1. Other Voltages available. Contact Micrel for detail.
Micrel, Inc. MIC5320
July 2006
4 M9999-073106
Pin Configuration
1VIN
GND
EN2
6 VOUT1
VOUT2
EN1
5
4
2
3
VIN GND
VOUT1 EN1
EN2
31
6
2
45
VOUT2
6-Pin 1.6mm x 1.6mm MLF (ML)
Top View
TSOT-23-6 (D6)
Top View
Pin Description
Pin Number
MLF-6
Pin Number
TSOT-23-6
Pin Name
Pin Function
1 3 VIN Supply Input.
2 2 GND Ground
3 1 EN2
Enable Input (regulator 2). Active High Input. Logic High = On; Logic Low = Off;
Do not leave floating.
4 6 EN1
Enable Input (regulator 1). Active High Input. Logic High = On; Logic Low = Off;
Do not leave floating.
5 5 VOUT2 Regulator Output – LDO2
6 4 VOUT1 Regulator Output – LDO1
Micrel, Inc. MIC5320
July 2006
5
M9999-073106
Absolute Maximum Ratings(1)
Supply Voltage (V
IN
) .....................................0V to +6V
Enable Input Voltage (V
EN
)...........................0V to +6V
Power Dissipation………………… Internally Limited
(3)
Lead Temperature (soldering, 3sec)..................260°C
Storage Temperature (T
S
)................ –65°C to +150°C
ESD Rating
(4)
.........................................................2kV
Operating Ratings(2)
Supply Voltage (V
IN
).............................. +2.3V to +5.5V
Enable Input Voltage (V
EN
).............................. 0V to V
IN
Junction Temperature (T
J
) ................. –40°C to +125°C
Junction Thermal Resistance
MLF-6 (θ
JA
).............................................. 100°C/W
TSOT-6 (θ
JA
) ........................................... 235°C/W
Electrical Characteristics(5)
V
IN
= EN1 = EN2 = V
OUT
+ 1.0V; higher of the two regulator outputs, I
OUTLDO1
= I
OUTLDO2
= 100µA; C
OUT1
= C
OUT2
= 1µF;
T
J
= 25°C, bold values indicate –40°C ≤ T
J
≤ +125°C, unless noted.
Parameter Conditions Min Typ Max Units
Variation from nominal V
OUT
-2.0
+2.0
% Output Voltage Accuracy
Variation from nominal V
OUT
; –40°C to +125°C
-3.0
+3.0
%
Line Regulation V
IN
= V
OUT
+ 1V to 5.5V; I
OUT
= 100µA 0.02 0.3
0.6
%/V
%/V
Load Regulation I
OUT
= 100µA to 150mA 0.5
2
%
Dropout Voltage
(6)
I
OUT
= 100µA
I
OUT
= 50mA
I
OUT
= 100mA
I
OUT
= 150mA
0.1
12
25
35
50
75
100
mV
mV
mV
mV
Ground Current EN1 = High; EN2 = Low; I
OUT
= 100µA to 150mA
EN1 = Low; EN2 = High; I
OUT
= 100µA to 150mA
EN1 = EN2 = High; I
OUT1
= 150mA, I
OUT2
= 150mA
85
85
150
120
120
190
µA
µA
µA
Ground Current in Shutdown EN1 = EN2 = 0V 0.01 2 µA
Ripple Rejection f = 1kHz; C
OUT
= 1.0µF
f=20kHz; C
OUT
= 1.0µF
65
45
dB
dB
Current Limit V
OUT
= 0V 300 550
950
mA
Output Voltage Noise C
OUT
= 1.0µF; 10Hz to 100KHz 90 µV
RMS
Enable Inputs (EN1 / EN2)
Logic Low
0.2
V Enable Input Voltage
Logic High
1.1
V
V
IL
≤ 0.2V 0.01 1 µA Enable Input Current
V
IH
≥ 1.0V 0.01 1 µA
Turn-on Time (See Timing Diagram)
Turn-on Time (LDO1 and 2) C
OUT
= 1.0µF 30
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. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
5. Specification for packaged product only.
6. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal V
OUT
. For
outputs below 2.3V,
the dropout voltage is the input-to-output differential with the minimum input voltage 2.3V.
Micrel, Inc. MIC5320
July 2006
6
M9999-073106
Functional Diagram
EN 1
Enable
Reference
LDO1
EN 2
LDO2
VIN VOUT 1
VOUT 2
GND
MIC5320 Block Diagram
Micrel, Inc. MIC5320
July 2006
7
M9999-073106
Typical Characteristics
0
-10
-20
-30
-40
-50
-60
-70
-80
Power Supply
Rejection Ratio
1
FREQUENCY (kHz)
0.1 10 100 1,000
V
IN
= V
OUT
+1V
V
OUT
= 2.8V
C
OUT
= 1µF
150mA
50mA
0
5
10
15
20
25
30
35
40
0 25 50 75 100 125 150
OUTPUT CURRENT (mA)
Dropout Voltage
vs. Output Current
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
EN1 = V
IN
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)
2.75
2.80
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
EN1 = V
IN
70
75
80
85
90
95
100
70 20 40 60 80
TEMPERATURE (°C)
Ground Current
vs. Temperature
100µA
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
EN1 = V
IN
EN2 = GND
70
75
80
85
90
95
100
70 20 40 60 80
TEMPERATURE (°C)
Ground Current
vs. Temperature
150mA
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
EN1 = V
IN
EN2 = GND
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0123456
INPUT VOLTAGE (V)
Output Voltage
vs. Input Voltage
2.8V
1.5V
2.5
I
OUT
= 100µA
C
OUT
= 1µF
40
45
50
Dropout Voltage
vs. Temperature
20 40 60 80
TEMPERATURE (°C)
100µA
10mA
50mA
100mA
150mA
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
0
5
10
15
20
25
30
35
2.70
2.75
2.80
2.85
2.90
0 25 50 75 100 125 150
OUTPUT CURRENT (mA)
Output Voltage
vs. Output Current
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT1
= C
OUT2
= 1µF
EN1 = V
IN
EN2 = GND
1.40
1.45
1.50
1.55
1.60
0 25 50 75 100 125 150
OUTPUT CURRENT (mA)
Output Voltage
vs. Output Current
V
IN
= V
OUT
+ 1V
V
OUT
= 1.5V
C
OUT1
= C
OUT2
= 1µF
EN1 = GND
EN2 = V
IN
70
75
80
85
90
0 25 50 75 100 125 150
OUTPUT CURRENT (mA)
Ground Current
vs. Output Current
V
IN
= V
OUT
+ 1V
V
OUT
= 2.85V
EN1 = V
IN
C
OUT1
= 1µF
142
146
150
154
158
162
0 25 50 75 100 125 150
OUTPUT CURRENT (mA)
Ground Current
vs. Output Current
V
IN
= V
OUT
+ 1V
V
OUT
= 2.85V
EN1 = EN2 = V
IN
C
OUT1
= C
OUT2
= 1µF
510
520
530
540
550
560
570
580
590
600
610
3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
Current Limit
vs. Input Voltage
EN1 = V
IN
C
OUT
= 1µF
Micrel, Inc. MIC5320
July 2006
8
M9999-073106
Typical Characteristics (continued)
0.001
0.01
0.1
10
Output Noise
Spectral Density
1
FREQUENCY (kHz)
0.10.01 10 100 1,000
V
IN
= 4V
V
OUT
= 2.8V
C
OUT
= 1µF
I
LOAD
= 50mA
Micrel, Inc. MIC5320
July 2006
9
M9999-073106
Functional Characteristics
Enable Turn-On
EN1
(1V/div)
VOUT1
(1V/div)
Time (10µs/div)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
Load Transient
Output Volta
g
e
(20mV/div)
Output Current
(50mA/div)
Time (40µs/div)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
150mA
10mA
Line Transient
Input Voltage
(2V/div)
Output Voltage
(50mV/div)
Time (40µs/div)
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
IOUT = 10mA
5.5V
4V
Micrel, Inc. MIC5320
July 2006
10
M9999-073106
Applications Information
Enable/Shutdown
The MIC5320 comes with dual active-high enable pins
that allow each regulator to be disabled
independently. 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 MIC5320 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
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.
Output Capacitor
The MIC5320 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 MIC5320
will remain stable and in regulation with no load. This
is especially important in CMOS RAM keep-alive
applications.
Thermal Considerations
The MIC5320 is designed to provide 150mA of
continuous current for both outputs in a very small
package. 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 3.3V, the output voltage is 2.8V for VOUT1,
1.5V for VOUT2 and the output current = 150mA. The
actual power dissipation of the regulator circuit can be
determined using the equation:
PD = (VIN – VOUT1) IOUT1 + (VIN – VOUT2) IOUT2+ VIN IGND
Because this device is CMOS and the ground current
is typically <150µA over the load range, the power
dissipation contributed by the ground current is < 1%
and can be ignored for this calculation.
PD = (3.3V – 2.8V) × 150mA + (3.3V -1.5) × 150mA
P
D = 0.345W
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
⎝
⎛
TJ(max) = 125°C, the maximum junction temperature of
the die θJA thermal resistance = 100°C/W.
The table below shows junction-to-ambient thermal
resistance for the MIC5320 in different packages.
Package
θ
JA
Recommended
Minimum
Footprint
θ
JC
6-Pin 1.6x1.6 MLF
®
100°C/W 2°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 100°C/W.
The maximum power dissipation must not be
exceeded for proper operation.
Micrel, Inc. MIC5320
July 2006 11
M9999-073106
For example, when operating the MIC5320-MFYML at
an input voltage of 3.3V and 150mA loads at each
output with a minimum footprint layout, the maximum
ambient operating temperature T
A
can be determined
as follows:
0.345W = (125°C – T
A
)/(100°C/W)
T
A
=90.5°C
Therefore, a 2.8V/1.5V application with 150mA at
each output current can accept an ambient operating
temperature of 90.5°C in a 1.6mm 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. MIC5320
July 2006 12
M9999-073106
Package Information
6-Pin 1.6mm x 1.6mm MLF (ML)
6-Pin TSOT-23 (D6)
Micrel, Inc. MIC5320
July 2006 13
M9999-073106
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.
© 2005 Micrel, Inc.
