2022 Microchip Technology Inc. and its subsidiaries DS20006678A-page 1
MIC5321
Features
• 2.3V to 5.5V Input Voltage Range
• Ultra-Low Dropout Voltage 35 mV @ 150 mA
• Tiny 6-Pin 1.6 mm x 1.6 mm Thin UDFN Leadless 
Package
• Low Cost 6-Lead TSOT-23 Package
• Bypass Pin for Improved Noise Performance
• High PSRR: >75 dB on Each LDO
• Ultra-Low Noise Output: >30 µVRMS
• Dual 150 mA Outputs
• µCap Stable with 1 µF Ceramic Capacitor
• Low Quiescent Current: 150 µA
• Fast Turn-On Time: 45 µs
• Thermal Shutdown Protection
• Current Limit Protection
Applications
• Mobile Phones
• PDAs
• GPS Receivers
• Portable Electronics
• Portable Media Players
• Digital Still and Video Cameras
General Description
The  MIC5321  is  a  tiny,  dual  ultra-low  dropout  linear
regulator ideally suited for applications that require high
PSRR because it provides a bypass pin for those noise
sensitive portable electronics. The MIC5321 integrates
two  high-performance  150 mA  ULDOs  into  a  very
compact  1.6 mm  x  1.6 mm  leadless  UDFN  package
that  provides  exceptional  thermal  package
characteristics. 
The MIC5321 is a µCap design that enables operation
with very small ceramic output capacitors for stability,
thereby reducing required board space and component
cost.  The  combination  of  extremely  low  dropout
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 is available in fixed-output voltages in the
tiny 6-pin 1.6 mm x 1.6 mm leadless UDFN package,
which is only 2.56 mm2 in area, less than 30% the area
of  the  SOT-23  and  TSOP  3x3  packages.  It’s  also
available in  the  thin  SOT-23 6-lead package  and  the
standard size 6-pin 1.6 mm x 1.6 mm leadless WDFN
package. Additional voltage options are available. For
more information, contact Microchip.
Package Types
MIC5321
6-Pin 1.6 mm x 1.6 mm UDFN (MT)/WDFN (ML)
(Top View)
MIC5321
6-Lead SOT-23 (D6)
(Top View)