PRELIMINARY
CALIFORNIA MICRO DEVICES
CM3151
Micropower, 500mA / 3.3V SmartOR
TM
Regulator with Drive
Features
3.3V regulated output up to 500mA in MSOP-8
package (150mA in SOT-23-6 package)
Automatic Detection of V
IN
Input Supply
Drive Output Logic to Control External PFET
Switch
<1 A quiescent current when V
IN
not present
“Zero” current in Shutdown mode
Built-In Hysteresis during Supply Selection
Thermal Overload Protection
Current Limiting Protection
Controller operates from either V
IN
or V
OUT
Pin Diagram
Applications
USB bus-powered handheld devices
PCI Adapter Cards
Product Description
TM
In
Package
Pins
8
6
Style
Power MSOP-8
SOT-23-6
The SmartOR CM3151 is a low dropout regulator
that delivers up to 500mA of load current in the
MSOP-8 package at a fixed 3.3V output. Continuous
output current is only limited by the package and the
layout (150mA max current in the SOT-23-6
package). An internal threshold level (typically 3.9V)
is used to prevent the regulator from being operated
below dropout voltage. The device continuously
monitors the input supply and will automatically
disable the regulator when V
IN
falls below the
threshold level. When the regulator is disabled, the
control signal “Drive” (Active Low) is enabled, which
allows an external PMOS switch to power the load
from a battery. When Vin is not present, the device
only draws less than 1 A from the output preventing
from discharging the battery.
When V
IN
is restored to a level above the select
threshold, the control signal for the external PMOS
switch is disabled and the regulator is once again
enabled.
The Enable input allows to shutdown the regulator
as well as sets the Drive signal “High” disabling the
external PMOS switch.
The CM3151 is available in an 8-pin MSOP
thermally enhanced package, or 6-pin SOT23 ideal
for space critical applications.
© 2004 California Micro Devices Corp. All rights reserved.
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Simplified Electrical Schematic
STANDARD PART ORDERING INFORMATION
Ordering Part Number
Tubes
Tape & Reel
Part Marking
www.calmicro.com
Typical Application Circuit (for MSOP-8)
C0590899
6/29/04
430 N. McCarthy Blvd., Milpitas, California 95035
1
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
