MIC5321
Dual, High Performance
150mA µCap 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-E
General Description
The MIC5321 is a tiny Dual Ultra Low-Dropout
(ULDO™) linear regulator ideally suited for those
applications that require high PSRR because it
provides a bypass pin for those noise sensitive
portable electronics. The MIC5321 integrates two
high-performance; 150mA ULDOs into a very compact
1.6mm x 1.6mm leadless Thin MLF
®
package that
provides exceptional thermal package characteristics.
The MIC5321 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, very high power supply
rejection, very low output noise and exceptional
thermal package characteristics makes it ideal for
powering RF application, cellular phone camera
modules, imaging sensors for digital still cameras,
PDAs, MP3 players and WebCam applications.
The MIC5321 ULDO™ is available in fixed-output
voltages in the tiny 6-pin 1.6mm x 1.6mm leadless
Thin 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 and the standard 6-pin
1.6mm x 1.6mm leadless package. Additional voltage
options are available. For more information, contact
Micrel marketing department.
Data sheets and support 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 Thin MLF
®
leadless
package
• Low cost TSOT-23-6 package
• Bypass pin for improved noise performance
• High PSRR – >75dB on each LDO
• Ultra low noise output - > 30µVrms
• Dual 150mA outputs
• µCap stable with 1µF ceramic capacitor
• Low quiescent current – 150µA
• Fast turn-on time – 45µs
• 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
VOUT 1
VOUT 2
GND
MIC5321-x.xYML
1µF
0.01µF
BYP 1µF
Rx/Synth
Tx
RF
Transceiver
1µF
RF Power Supply Circuit
Micrel, Inc. MIC5321
May 2008 2 M9999-051508-E
Ordering Information
Part number
Manufacturing
Part Number
Marking*
Voltage**
Junction
Temp. Range
Package
MIC5321-1.8/1.5YMT MIC5321-GFYMT BGF 1.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-1.8/1.8YMT MIC5321-GGYMT BGG 1.8V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-1.8/1.6YMT MIC5321-GWYMT BGW 1.8V/1.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.5/1.8YMT MIC5321-JGYMT BJG 2.5V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.5/2.5YMT MIC5321-JJYMT BJJ 2.5V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.6/1.85YMT MIC5321-KDYMT BKD 2.6V/1.85 –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.6/1.8YMT MIC5321-KGYMT BKG 2.6V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.7/2.7YMT MIC5321-LLYMT BLL 2.7V/2.7V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.8/1.5YMT MIC5321-MFYMT BMF 2.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.8/1.8YMT MIC5321-MGYMT BMG 2.8V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.8/2.6YMT MIC5321-MKYMT BMK 2.8V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.8/2.8YMT MIC5321-MMYMT BMM 2.8V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.85/1.85YMT MIC5321-NDYMT BND 2.85V/1.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.85/2.6YMT MIC5321-NKYMT BNK 2.85V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.85/2.85YMT MIC5321-NNYMT BNN 2.85V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.9/1.5YMT MIC5321-OFYMT BOF 2.9V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.9/1.8YMT MIC5321-OGYMT BOG 2.9V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.9/2.9YMT MIC5321-OOYMT BOO 2.9V/2.9V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.0/1.8YMT MIC5321-PGYMT BPG 3.0V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.0/2.5YMT MIC5321-PJYMT BPJ 3.0V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.0/2.6YMT MIC5321-PKYMT BPK 3.0V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.0/2.8YMT MIC5321-PMYMT BPM 3.0V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.0/2.85YMT MIC5321-PNYMT BPN 3.0V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.0/3.0YMT MIC5321-PPYMT BPP 3.0V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/1.5YMT MIC5321-SFYMT BSF 3.3V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/1.8YMT MIC5321-SGYMT BSG 3.3V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/2.5YMT MIC5321-SJYMT BSJ 3.3V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/2.6YMT MIC5321-SKYMT BSK 3.3V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/2.7YMT MIC5321-SLYMT*** BSL 3.3V/2.7V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/2.8YMT MIC5321-SMYMT BSM 3.3V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/2.85YMT MIC5321-SNYMT BSN 3.3V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/2.9YMT MIC5321-SOYMT BSO 3.3V/2.9V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/3.0YMT MIC5321-SPYMT BSP 3.3V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/3.2YMT MIC5321-SRYMT BSR 3.3V/3.2V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-3.3/3.3YMT MIC5321-SSYMT BSS 3.3V/3.3V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF
®
MIC5321-2.8/1.5YML MIC5321-MFYML BMF 2.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5321-2.8/1.8YML MIC5321-MGYML BMG 2.8V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5321-2.8/2.8YML MIC5321-MMYML BMM 2.8V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
MIC5321-3.0/3.0YML MIC5321-PPYML BPP 3.0V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 MLF
®
Micrel, Inc. MIC5321
May 2008 3 M9999-051508-E
Part number
Manufacturing
Part Number
Marking*
Voltage**
Junction
Temp. Range
Package
MIC5321-1.8/1.5YD6 MIC5321-GFYD6 QBGF 1.8V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-1.8/1.8YD6 MIC5321-GGYD6 QBGG 1.8V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-1.8/1.6YD6 MIC5321-GWYD6*** QBGW 1.8V/1.6V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.5/1.8YD6 MIC5321-JGYD6*** QBJG 2.5V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.5/2.5YD6 MIC5321-JJYD6*** QBJJ 2.5V/2.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.6/1.85YD6 MIC5321-KDYD6*** QBKD 2.6V/1.85 –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.6/1.8YD6 MIC5321-KGYD6*** QBKG 2.6V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.7/2.7YD6 MIC5321-LLYD6 QBLL 2.7V/2.7V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.8/1.5YD6 MIC5321-MFYD6 QBMF 2.8V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.8/1.8YD6 MIC5321-MGYD6 QBMG 2.8V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.8/2.6YD6 MIC5321-MKYD6 QBMK 2.8V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.8/2.8YD6 MIC5321-MMYD6 QBMM 2.8V/2.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.85/1.85YD6 MIC5321-NDYD6*** QBND 2.85V/1.85V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.85/2.6YD6 MIC5321-NKYD6*** QBNK 2.85V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.85/2.85YD6 MIC5321-NNYD6*** QBNN 2.85V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.9/1.5YD6 MIC5321-OFYD6*** QBOF 2.9V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.9/1.8YD6 MIC5321-OGYD6*** QBOG 2.9V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-2.9/2.9YD6 MIC5321-OOYD6*** QBOO 2.9V/2.9V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.0/1.8YD6 MIC5321-PGYD6 QBPG 3.0V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.0/2.5YD6 MIC5321-PJYD6*** QBPJ 3.0V/2.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.0/2.6YD6 MIC5321-PKYD6*** QBPK 3.0V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.0/2.8YD6 MIC5321-PMYD6*** QBPM 3.0V/2.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.0/2.85YD6 MIC5321-PNYD6*** QBPN 3.0V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.0/3.0YD6 MIC5321-PPYD6 QBPP 3.0V/3.0V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/1.5YD6 MIC5321-SFYD6*** QBSF 3.3V/1.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/1.8YD6 MIC5321-SGYD6*** QBSG 3.3V/1.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/2.5YD6 MIC5321-SJYD6 QBSJ 3.3V/2.5V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/2.6YD6 MIC5321-SKYD6*** QBSK 3.3V/2.6V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/2.7YD6 MIC5321-SLYD6*** QBSL 3.3V/2.7V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/2.8YD6 MIC5321-SMYD6*** QBSM 3.3V/2.8V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/2.85YD6 MIC5321-SNYD6*** QBSN 3.3V/2.85V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/2.9YD6 MIC5321-SOYD6*** QBSO 3.3V/2.9V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/3.0YD6 MIC5321-SPYD6*** QBSP 3.3V/3.0V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/3.2YD6 MIC5321-SRYD6*** QBSR 3.3V/3.2V –40°C to +125°C 6-Pin TSOT-23
MIC5321-3.3/3.3YD6 MIC5321-SSYD6 QBSS 3.3V/3.3V –40°C to +125°C 6-Pin TSOT-23
Notes
* Under bar ( _ )/Over bar ( ¯ ) symbol may not be to scale. Thin MLF (MT) package Pin 1 identified = ▲.
** For other voltages available. Contact Micrel for more details.
*** Contact Micrel Marketing for availability.
Micrel, Inc. MIC5321
May 2008 4 M9999-051508-E
Pin Configuration
1VIN
GND
BYP
6 VOUT1
VOUT2
EN
5
4
2
3
VIN GND
VOUT1 EN
BYP
31
6
2
45
VOUT2
6-Pin 1.6mm x 1.6mm Thin MLF (MT) / MLF (ML)
Top View
TSOT-23-6 (D6)
Top View
Pin Description
Pin Number
Thin MLF-6 /
MLF-6
Pin Number
TSOT-23-6
Pin Name
Pin Function
1 3 VIN Supply Input.
2 2 GND Ground
3 1 BYP
Reference Bypass: Connect external 0.01µF to GND to reduce output noise.
May be left open.
4 6 EN
Enable Input (both regulators): 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
HS Pad – EPAD Exposed heatsink pad connected to ground internally.
Micrel, Inc. MIC5321
May 2008 5
M9999-051508-E
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
Thin MLF-6 / MLF-6 (θ
JA
) ....................... 100°C/W
TSOT-6 (θ
JA
) ........................................... 235°C/W
Electrical Characteristics(5)
V
IN
= EN = V
OUT
+ 1.0V; higher of the two regulator outputs, I
OUTLDO1
= I
OUTLDO2
= 100µA; C
OUT1
= C
OUT2
= 1µF;
C
BYP
= 0.01µF; 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
2.0
%
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 EN = High; I
OUT1
= 150mA, I
OUT2
= 150mA 150
190
µA
Ground Current in Shutdown EN1 ≤ 0.2V 0.01
2
µA
Ripple Rejection f = 1kHz; C
OUT
= 1.0µF; C
BYP
= 0.1µF
f = 20kHz; C
OUT
= 1.0µF; C
BYP
= 0.1µF
75
45
dB
dB
Current Limit V
OUT
= 0V
300
550
950
mA
Output Voltage Noise C
OUT
= 1.0µF; C
BYP
= 0.01µF; 10Hz to 100kHz 30 µV
RMS
Enable Inputs (EN)
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; No C
BYP
C
OUT
= 1.0µF; C
BYP
= 0.01µF
40
45
100
100
µs
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 it’s 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. MIC5321
May 2008 6
M9999-051508-E
Functional Diagram
EN
Enable
Reference
LDO1
LDO2
BYP
VIN VOUT 1
VOUT 2
GND
MIC5321 Block Diagram
Micrel, Inc. MIC5321
May 2008 7
M9999-051508-E
Typical Characteristics
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
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
C
BYP
= 0.1µF
50mA
150mA
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
OUT
= 2.8V
C
OUT
= 1µF
V
IN
= V
OUT
+ 1V
EN = 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
EN = V
IN
120
125
130
140
145
150
155
160
20 40 60 80
TEMPERATURE (°C)
Ground Current
vs. Temperature
100µA
V
IN
= V
OUT
+ 1V
V
OUT
= 3V
C
OUT
= 1µF
EN = V
IN
135
120
125
130
145
150
155
160
Ground Current
vs. Temperature
20 40 60 80
TEMPERATURE (°C)
150mA
V
IN
= V
OUT
+ 1V
V
OUT
= 3V
C
OUT
= 1µF
EN = V
IN
135
140
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
35
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
5
10
15
20
25
30
0
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
EN = V
IN
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
EN = V
IN
138
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
EN = 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
EN = V
IN
C
OUT
= 1µF
0.001
0.01
0.1
1
10
Output Noise
Spectral Density
1
FREQUENCY (kHz)
0.10.01 10 100 1,000 10,000
V
IN
= 3.8V
V
OUT
= 2.8V
C
OUT
= 1µF
C
BYP
= 0.01µF
Micrel, Inc. MIC5321
May 2008 8
M9999-051508-E
Functional Characteristics
Enable Turn-On
Enable
(1V/div)
VOUT2
(1V/div)
Time (10µs/div)
VOUT1
(1V/div)
V
IN
= V
OUT
+ 1V
V
OUT1
= V
OUT2
= 3.0V
C
OUT
= 1µF
C
BYP
= 0.1µF
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
C
BYP
= 0.1µF
Line Transient
Input Volta
g
e
(2V/div)
Output Volta
g
e
(50mV/div)
Time (40µs/div)
V
IN
= V
OUT
+ 1V
V
OUT
= 2.8V
C
OUT
= 1µF
I
OUT
= 10mA
5.5V
4V
Micrel, Inc. MIC5321
May 2008 9
M9999-051508-E
Applications Information
Enable/Shutdown
The MIC5321 comes with a single active-high enable
pin that allows both regulators to be disabled
simultaneously. 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 MIC5321 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 MIC5321 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 perform-
ance. 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.
Bypass Capacitor
A capacitor can be placed from the noise bypass pin
to ground to reduce output voltage noise. The
capacitor bypasses the internal reference. A 0.1µF
capacitor is recommended for applications that require
low-noise outputs. The bypass capacitor can be
increased, further reducing noise and improving
PSRR. Turn-on time increases slightly with respect to
bypass capacitance. A unique, quick-start circuit
allows the MIC5321 to drive a large capacitor on the
bypass pin without significantly slowing turn-on time.
Refer to the Typical Characteristics section for
performance with different bypass capacitors.
No-Load Stability
Unlike many other voltage regulators, the MIC5321
will remain stable and in regulation with no load. This
is especially important in CMOS RAM keep-alive
applications.
Thermal Considerations
The MIC5321 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,
2.5V 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 MIC5321 in the Thin MLF® package.
Package θ
JA
Recommended
Minimum Footprint θ
JC
6-Pin 1.6x1.6 Thin MLF
®
100°C/W 2°C/W
Thermal Resistance
Micrel, Inc. MIC5321
May 2008 10
M9999-051508-E
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.
For example, when operating the MIC5321-MFYMT 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 Thin
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. MIC5321
May 2008 11
M9999-051508-E
Package Information
6-Pin 1.6mm x 1.6mm Thin MLF (MT)
6-Pin 1.6mm x 1.6mm MLF (ML)
Micrel, Inc. MIC5321
May 2008 12
M9999-051508-E
6-Pin TSOT-23 (D6)
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, Inc.
Mouser Electronics
Authorized Distributor
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MIC5321-NKYMT TR MIC5321-MFYMT TR MIC5321-GWYMT TR MIC5321-PNYMT TR MIC5321-SNYMT TR
MIC5321-SLYD6 TR MIC5321-SJYD6 TR MIC5321-KDYMT TR MIC5321-PPYMT TR MIC5321-LLYML TR
MIC5321-SRYMT TR MIC5321-MFYML TR MIC5321-NDYMT TR MIC5321-SSYMT TR MIC5321-PGYMT TR
MIC5321-GGYMT TR MIC5321-MMYD6 TR MIC5321-PMYMT TR MIC5321-JJYMT TR MIC5321-MGYML TR
MIC5321-SGYMT TR MIC5321-PGYD6 TR MIC5321-LLYD6 TR MIC5321-MKYMT TR MIC5321-MFYD6 TR
MIC5321-SSYML TR MIC5321-GGYD6 TR MIC5321-SFYMT TR MIC5321-MMYMT TR MIC5321-SOYMT TR
MIC5321-PPYD6 TR MIC5321-JGYMT TR MIC5321-PJYMT TR MIC5321-LLYMT TR MIC5321-46MYD6 TR
MIC5321-KGYMT TR MIC5321-SJYML TR MIC5321-PKYMT TR MIC5321-SKYMT TR MIC5321-SMYMT TR
MIC5321-OFYMT TR MIC5321-SLYMT TR MIC5321-OOYMT TR MIC5321-NNYMT TR MIC5321-MMYML TR
MIC5321-MKYD6 TR MIC5321-MGYMT TR MIC5321-OGYMT TR MIC5321-GFYD6 TR MIC5321-PPYML TR
MIC5321-46MYMT TR MIC5321-SPYMT TR MIC5321-SJYMT TR MIC5321-MGYD6 TR MIC5321-SSYD6 TR
MIC5321-GFYMT TR MIC5321-PGYMT-TR MIC5321-KGYMT-TR MIC5321-LLYML-TR MIC5321-SKYMT-TR
MIC5321-SLYD6-TR MIC5321-PKYMT-TR MIC5321-GFYMT-TR MIC5321-46MYMT-TR MIC5321-SLYMT-TR
MIC5321-SSYML-TR MIC5321-SJYMT-TR MIC5321-46MYD6-TR MIC5321-GGYD6-TR MIC5321-GFYD6-TR
MIC5321-GGYMT-TR MIC5321-MMYD6-TR MIC5321-PPYD6-TR MIC5321-SPYMT-TR MIC5321-SGYMT-TR
MIC5321-SRYMT-TR MIC5321-SSYMT-TR MIC5321-MGYMT-TR MIC5321-PPYML-TR MIC5321-MFYD6-TR
MIC5321-MGYML-TR MIC5321-MKYD6-TR MIC5321-NKYMT-TR MIC5321-SMYMT-TR MIC5321-SNYMT-TR
MIC5321-SOYMT-TR MIC5321-NNYMT-TR MIC5321-PMYMT-TR MIC5321-OFYMT-TR MIC5321-PPYMT-TR
MIC5321-JJYMT-TR MIC5321-LLYD6-TR MIC5321-GWYMT-TR MIC5321-PGYD6-TR MIC5321-SJYD6-TR
MIC5321-MGYD6-TR MIC5321-SFYMT-TR MIC5321-JGYMT-TR MIC5321-MFYMT-TR MIC5321-PNYMT-TR
