MIC94325 Datasheet, PDF (1/16 Pages) Micrel Semiconductor – 500mA LDO with Ripple Blocker Technology

MIC94325/45/55
500mA LDO with
Ripple Blocker Technology
General Description
Features
The MIC943x5 Ripple Blocker is a monolithic integrated
circuit that provides low-frequency ripple attenuation
(switching noise rejection) to a regulated output voltage.
This is important for applications where a DC/DC switching
converter is required to lower or raise a battery voltage but
where switching noise cannot be tolerated by sensitive
 1.8V to 3.6V input voltage range
 Active noise rejection over a wide frequency band
 >50dB from 10Hz to 5MHz at 500mA load
 Rated to 500mA output current
 Fixed and adjustable output voltages
downstream circuits such as in RF applications. The
MIC943x5 maintains high power supply ripple rejection
(PSRR) with input voltages operating near the output
voltage level to improve overall system efficiency. A low-
voltage logic enable pin facilitates ON/OFF control at
 Optional output auto-discharge when disabled
 Current-limit and thermal-limit protected
 Ultra-small 0.84mm x 1.32mm 6-ball CSP
 1.6mm x 1.6mm, 6-pin Thin DFN
typical GPIO voltage levels.
 Logic-controlled enable pin
The MIC943x5 operates from an input voltage of 1.8V to  40C to +125C junction temperature range
3.6V. The MIC943x5 options include fixed (MIC94345/55)
or adjustable (MIC94325) output voltages. The MIC94355
version offers an auto-discharge to discharge the output
Applications
capacitor when the part is disabled.
 Smart phones
Packaged in a 0.84mm x 1.32mm 6-ball CSP or a 6-pin
1.6mm x 1.6mm Thin DFN, the MIC943x5 has a junction
operating temperature range of –40C to +125C.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
 Tablet PC/notebooks and webcams
 Digital still and video cameras
 Global positioning systems
 Mobile computing
 Automotive and industrial applications
_________________________________________________________________________________________________
Typical Application
MIC94355 PSRR
C_OUT = 4.7µF
0
V_IN = 2.8V + 40mVpp
-20 V_OUT = 1.8V
COUT = 4.7µF
-40
500mA
-60
-80
10mA
-100
-120
10
200mA
100 1,10K00 101,00K00 1010,00K0 1,010M0,0 1100,0M00,
0
00 000
FREQUENCY (Hz)
Ripple Blocker is a trademark of Micrel, Inc
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
October 2012
M9999-102512-A