Semiconductor Components Industries, LLC, 2005
March, 2005 − Rev. 5
1 Publication Order Number:
MC3423/D
MC3423
Overvoltage Crowbar
Sensing Circuit
This overvoltage protection circuit (OVP) protects sensitive
electronic circuitry from overvoltage transients or regulator failures
when used in conjunction with an external “crowbar” SCR. The
device senses the overvoltage condition and quickly “crowbars” or
short circuits the supply, forcing the supply into current limiting or
opening the fuse or circuit breaker.
The protection voltage threshold is adjustable and the MC3423 can
be programmed for minimum duration of overvoltage condition
before tripping, thus supplying noise immunity.
The MC3423 is essentially a “two terminal” system, therefore it
can be used with either positive or negative supplies.
Features
• Pb−Free Package is Available
MAXIMUM RATINGS
Rating Symbol Value Unit
Differential Power Supply Voltage V
CC
−V
EE
40 Vdc
Sense Voltage (1) V
Sense1
6.5 Vdc
Sense Voltage (2) V
Sense2
6.5 Vdc
Remote Activation Input Voltage V
act
7.0 Vdc
Output Current I
O
300 mA
Operating Ambient Temperature Range T
A
0 to +70 °C
Operating Junction Temperature T
J
125 °C
Storage Temperature Range T
stg
−65 to +150 °C
Maximum ratings are those values beyond which device damage can occur.
Maximum ratings applied to the device are individual stress limit values (not
normal operating conditions) and are not valid simultaneously. If these limits
are exceeded, device functional operation is not implied, damage may occur
and reliability may be affected.
Figure 1. Simplified Application
V
out
V
in
C
out
Current
Limited
DC
Power
Supply
O. V. P.
MC3423
+
MARKING
DIAGRAMS
MC3423P1 = Device Code
A = Assembly Location
WL = Wafer Lot
YY = Year
WW = Work Week
SOIC−8
D SUFFIX
PLASTIC PACKAGE
CASE 751
PIN CONNECTIONS
1
2
3
45
6
7
8V
CC
Sense 1
Sense 2
Current
Source
Drive
Output
V
EE
Indicator
Output
Remote
Activation
(Top View)
See detailed ordering and shipping information in the package
dimensions section on page 7 of this data sheet.
ORDERING INFORMATION
3423
ALYW
1
8
1
8
MC3423P1
AWL
YYWW
3423 = Device Code
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
1
8
PDIP−8
P1 SUFFIX
PLASTIC PACKAGE
CASE 626
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