Micrel MIC5321 Dual, high performance 150ma ucap uldo Datasheet

MIC5321
Dual, High Performance 150mA µCap ULDO™
General Description
Features
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 2.56mm2 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.
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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
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Data sheets and support documentation can be found
on Micrel’s web site at www.micrel.com.
Mobile phones
PDAs
GPS receivers
Portable electronics
Portable media players
Digital still and video cameras
Typical Application
MIC5321-x.xYML
VIN
1µF
VOUT 1
Rx/Synth
VOUT 2
Tx
EN
BYP
GND
1µF
1µF
RF
Transceiver
0.01µF
RF Power Supply Circuit
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
January 2007
M9999-012407-C
Micrel, Inc.
MIC5321
Ordering Information
Part number
Manufacturing
Part Number
MIC5321-1.8/1.5YMT
MIC5321-GFYMT
MIC5321-1.8/1.6YMT
Voltage
Junction
Temp. Range
BGF
1.8V/1.5V
–40°C to +125°C
6-Pin 1.6x1.6 Thin MLF®
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®
MIC5321-2.8/2.85YMT
MIC5321-MNYMT
BMN
2.8V/2.85V
–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®
January 2007
Marking*
2
Package
®
®
M9999-012407-C
Micrel, Inc.
Part number
MIC5321
Marking*
MIC5321-1.8/1.5YD6
Manufacturing
Part Number
MIC5321-GFYD6
Voltage
QBGF
MIC5321-1.8/1.6YD6
MIC5321-GWYD6
QBGW
MIC5321-2.5/1.8YD6
MIC5321-JGYD6
MIC5321-2.5/2.5YD6
MIC5321-JJYD6
MIC5321-2.6/1.85YD6
MIC5321-KDYD6
MIC5321-2.6/1.8YD6
MIC5321-KGYD6
MIC5321-2.7/2.7YD6
MIC5321-LLYD6
QBLL
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
MIC5321-2.8/2.85YD6
MIC5321-MNYD6
QBMN
2.8V/2.85V
–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
Package
1.8V/1.5V
Junction
Temp. Range
–40°C to +125°C
6-Pin TSOT-23
1.8V/1.6V
–40°C to +125°C
6-Pin TSOT-23
QBJG
2.5V/1.8V
–40°C to +125°C
6-Pin TSOT-23
QBJJ
2.5V/2.5V
–40°C to +125°C
6-Pin TSOT-23
QBKD
2.6V/1.85
–40°C to +125°C
6-Pin TSOT-23
QBKG
2.6V/1.8V
–40°C to +125°C
6-Pin TSOT-23
2.7V/2.7V
–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
Note:
*
Under bar/Over bar symbol may not be to scale.
** For other voltages available. Contact Micrel Marketing for details.
January 2007
3
M9999-012407-C
Micrel, Inc.
MIC5321
Pin Configuration
VIN 1
6
VOUT1
GND 2
5
VOUT2
BYP 3
4
EN
VIN
GND
BYP
3
2
1
4
5
6
VOUT1 VOUT2
6-Pin 1.6mm x 1.6mm Thin MLF (MT)
Top View
EN
TSOT-23-6 (D6)
Top View
Pin Description
Pin Number
Thin 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
5
5
VOUT2
Regulator Output – LDO2
6
4
VOUT1
Regulator Output – LDO1
January 2007
Enable Input (both regulators): Active High Input. Logic High = On; Logic
Low = Off; Do not leave floating.
4
M9999-012407-C
Micrel, Inc.
MIC5321
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VIN) .....................................0V to +6V
Enable Input Voltage (VEN)...........................0V to +6V
Power Dissipation………………….Internally Limited(3)
Lead Temperature (soldering, 3sec) ..................260°C
Storage Temperature (TS) ................ –65°C to +150°C
ESD Rating(4) .........................................................2kV
Supply Voltage (VIN).............................. +2.3V to +5.5V
Enable Input Voltage (VEN).............................. 0V to VIN
Junction Temperature (TJ) ................. –40°C to +125°C
Junction Thermal Resistance
Thin MLF-6 (θJA) ..................................... 100°C/W
TSOT-6 (θJA) ........................................... 235°C/W
Electrical Characteristics(5)
VIN = EN = VOUT + 1.0V; higher of the two regulator outputs, IOUTLDO1 = IOUTLDO2 = 100µA; COUT1 = COUT2 = 1µF;
CBYP = 0.01µF; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted.
Parameter
Conditions
Output Voltage Accuracy
Min
Typ
Max
Units
Variation from nominal VOUT
-2.0
+2.0
%
Variation from nominal VOUT; –40°C to +125°C
-3.0
+3.0
%
VIN = VOUT + 1V to 5.5V; IOUT = 100µA
0.02
0.3
0.6
%/V
%/V
IOUT = 100µA to 150mA
0.5
2.0
%
IOUT = 100µA
0.1
IOUT = 50mA
12
IOUT = 100mA
IOUT = 150mA
Ground Current
Line Regulation
Load Regulation
Dropout Voltage
(6)
mV
50
mV
25
75
mV
35
100
mV
EN = High; IOUT1 = 150mA, IOUT2 = 150mA
150
190
µA
Ground Current in Shutdown
EN1 ≤ 0.2V
0.01
2
µA
Ripple Rejection
f = 1kHz; COUT = 1.0µF; CBYP = 0.1µF
75
dB
f = 20kHz; COUT = 1.0µF; CBYP = 0.1µF
45
dB
300
Current Limit
VOUT = 0V
Output Voltage Noise
COUT = 1.0µF; CBYP = 0.01µF; 10Hz to 100kHz
550
950
30
mA
µVRMS
Enable Inputs (EN)
Enable Input Voltage
0.2
Logic Low
1.1
Logic High
Enable Input Current
V
V
VIL ≤ 0.2V
0.01
1
µA
VIH ≥ 1.0V
0.01
1
µA
COUT = 1.0µF; No CBYP
40
100
µs
COUT = 1.0µF; CBYP = 0.01µF
45
100
µs
Turn-on Time (See Timing Diagram)
Turn-on Time (LDO1 and 2)
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 TA (ambient temperature) is PD(max) = (TJ(max) – TA) / θJA. 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 VOUT. For outputs below 2.3V,
the dropout voltage is the input-to-output differential with the minimum input voltage 2.3V
January 2007
5
M9999-012407-C
Micrel, Inc.
MIC5321
Functional Diagram
VIN
VOUT 1
LDO1
LDO2
VOUT 2
EN
Enable
BYP
Reference
GND
MIC5321 Block Diagram
January 2007
6
M9999-012407-C
Micrel, Inc.
MIC5321
Typical Characteristics
-90
Power Supply
Rejection Ratio
40
-80
35
-70
30
-60
50mA
-40
V =V
+1V
150mA
-20 VIN =OUT
OUT 2.8V
-10 COUT = 1µF
CBYP = 0.1µF
0
0.1
1
10
100
1,000
FREQUENCY (kHz)
20
Ground Current
vs. Temperature
10
5
0
0
160
155
155
150
150
100µA
145
145
140
140
135
135
VIN = VOUT + 1V
VOUT = 3V
COUT = 1µF
EN = VIN
130
125
20 40 60 80
TEMPERATURE (°C)
Dropout Voltage
vs. Temperature
50
VIN = VOUT + 1V
45 VOUT = 2.8V
C
40 OUT = 1µF
35
30
25
20
15
10
5
0
162
120
2.90
25 50 75 100 125 150
OUTPUT CURRENT (mA)
Ground Current
vs. Temperature
100µA
20 40 60 80
TEMPERATURE (°C)
Ground Current
vs. Output Current
150
VIN = VOUT + 1V
VOUT = 2.85V
EN = VIN
COUT1 = COUT2 = 1µF
142
25 50 75 100 125 150
OUTPUT CURRENT (mA)
January 2007
2.55
2.50
3.0
2.5
150mA
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
EN = VIN
20 40 60 80
TEMPERATURE (°C)
Output Voltage
vs. Input Voltage
2.8V
2.0
1.5
VIN = VOUT + 1V
VOUT = 3V
COUT = 1µF
EN = VIN
20 40 60 80
TEMPERATURE (°C)
Output Voltage
vs. Output Current
1.5V
1.0
0.5
0.0
0
1.60
IOUT = 100µA
COUT = 1µF
1
2
3
4
5
6
INPUT VOLTAGE (V)
Output Voltage
vs. Output Current
2.85
1.55
2.80
1.50
2.75 VIN = VOUT + 1V
VOUT = 2.8V
COUT1 = COUT2 = 1µF
EN = VIN
2.70
0
25 50 75 100 125 150
OUTPUT CURRENT (mA)
1.45 VIN = VOUT + 1V
VOUT = 1.5V
COUT1 = COUT2 = 1µF
EN = VIN
1.40
0
25 50 75 100 125 150
OUTPUT CURRENT (mA)
610
600
Current Limit
vs. Input Voltage
10
590
580
570
560
154
146
2.70
2.65
2.60
100mA
158
138
0
125
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
EN = VIN
150mA
50mA
10mA
130
Output Voltage
vs. Temperature
2.90
2.85
2.80
2.75
15
-30
120
3.00
2.95
25
-50
160
Dropout Voltage
vs. Output Current
1
0.1
550
540
530
520
510
3
Output Noise
Spectral Density
EN = VIN
COUT = 1µF
3.5
4
4.5
5
INPUT VOLTAGE (V)
7
5.5
0.01 VIN = 3.8V
VOUT = 2.8V
COUT = 1µF
CBYP = 0.01µF
0.001
0.01 0.1 1
10 100 1,000 10,000
FREQUENCY (kHz)
M9999-012407-C
Micrel, Inc.
MIC5321
Functional Characteristics
Enable Turn-On
Enable
(1V/div)
Output Voltage
(20mV/div)
Load Transient
150mA
VIN = VOUT + 1V
VOUT = 2.8V
VOUT1
(1V/div)
COUT = 1µF
Output Current
(50mA/div)
CBYP = 0.1µF
VOUT2
(1V/div)
VIN = VOUT + 1V
VOUT1 = VOUT2 = 3.0V
COUT = 1µF
CBYP = 0.1µF
10mA
Time (10µs/div)
Time (40µs/div)
Line Transient
5.5V
Input Voltage
(2V/div)
4V
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
Output Voltage
(50mV/div)
IOUT = 10mA
Time (40µs/div)
January 2007
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M9999-012407-C
Micrel, Inc.
MIC5321
Applications Information
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.
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-modecurrent 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.
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.
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 highfrequency capacitors, such as small-valued NPO
dielectric-type capacitors, help filter out highfrequency noise and are good practice in any RFbased circuit.
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:
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.
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
PD = 0.345W
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.
To determine the maximum ambient operating
temperature of the package, use the junction-toambient thermal resistance of the device and the
following basic equation:
PD(MAX) =
TJ(MAX) - TA
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.
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
January 2007
⎛
⎝
9
M9999-012407-C
Micrel, Inc.
MIC5321
Package
6-Pin 1.6x1.6 Thin MLF
®
θJA Recommended
Minimum Footprint
θJC
100°C/W
2°C/W
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 TA can be determined
as follows:
Thermal Resistance
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 100°C/W.
The maximum power dissipation must not be
exceeded for proper operation.
0.345W = (125°C – TA)/(100°C/W)
TA=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
January 2007
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M9999-012407-C
Micrel, Inc.
MIC5321
Package Information
6-Pin 1.6mm x 1.6mm Thin MLF (MT)
6-Pin TSOT-23 (D6)
January 2007
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M9999-012407-C
Micrel, Inc.
MIC5321
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.
January 2007
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M9999-012407-C
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