NCP345
Overvoltage Protection IC
The NCP345 overvoltage protection circuit (OVP) protects
sensitive electronic circuitry from overvoltage transients and power
supply faults when used in conjunction with an external P−channel
FET. The device is designed to sense an overvoltage condition and
quickly disconnect the input voltage supply from the load before any
damage can occur. The OVP consists of a precise voltage reference, a
comparator with hysteresis, control logic, and a MOSFET gate driver.
The OVP is designed on a robust BiCMOS process and is intended to
withstand voltage transients up to 30 V.
The device is optimized for applications that have an external
AC/DC adapter or car accessory charger to power the product and/or
recharge the internal batteries. The nominal overvoltage threshold is
6.85 V so it is suitable for single cell Li−Ion applications as well as 3/4
cell NiCD/NiMH applications.
Features
http://onsemi.com
5
1
THIN SOT−23−5
SN SUFFIX
CASE 483
PIN CONNECTIONS &
MARKING DIAGRAM
OUT 1
RADYW
GND
CNTRL
2
3
Y
W
5
VCC
•
•
•
•
•
•
•
•
•
Overvoltage Turn−Off Time of less than 1.0
msec
Accurate Voltage Threshold of 6.85 V (nominal)
Undervoltage Lockout Protection
CNTRL Input Compatible with 1.8 V Logic Levels
Pb−Free Package is Available
4
IN
= Year
= Work Week
(Top View)
Typical Applications
Cellular Phones
Digital Cameras
Portable Computers and PDAs
Portable CD and other Consumer Electronics
ORDERING INFORMATION
Device
NCP345SNT1
NCP345SNT1G
Package
SOT−23−5
SOT−23−5
(Pb−Free)
Shipping
†
3000 / Tape &
Reel
(7 inch Reel)
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
Schottky
Diode
AC/DC Adapter or
Accessory Charger
V
CC
IN
+
−
V
ref
NCP345
GND
CNTRL
Undervoltage
Lock Out
P−CH
+
Logic
FET
Driver
C1
OUT
LOAD
Microprocessor port
Note: This device contains 89 active transistors
Figure 1. Simplified Application Diagram
©
Semiconductor Components Industries, LLC, 2004
1
December, 2004 − Rev. 5
Publication Order Number:
NCP345/D
ONSEMI [ ON SEMICONDUCTOR ]
