CS8122
CS8122
2% 5V, 750mA Low Dropout Linear
Regulator with Delayed RESET
Description
The CS8122 is a precision 5V linear reg-
ulator capable of sourcing in excess of
750mA. The
RESET
Õs delay time is
externally programmed using a discrete
RC network. During power up, or when
the output goes out of regulation, the
RESET
lead remains in the low state
for the duration of the delay. This func-
tion is independent of the input voltage
and will function correctly as long as
the output voltage remains at or above
1V. Hysteresis is included in the Delay
and the
RESET
comparators to
improve noise immunity. A latching
discharge circuit is used to discharge
the delay capacitor when it is triggered
by a brief fault condition.
The regulator is protected against a
variety of fault conditions: i.e. reverse
battery, overvoltage, short circuit and
thermal runaway conditions. The regu-
lator is protected against voltage tran-
sients ranging from -50V to +40V. Short
circuit current is limited to 1.2A (typ).
The CS8122 is an improved replacement
for the CS8126 and features a tighter tol-
erance on its output voltage (2% vs 4%).
The CS8122 is packaged in a 5 lead
TOÐ220 with copper tab. The copper tab
can be connected to a heat sink if
necessary.
Features
s
5V +/- 2% Regulated
Output
s
Low Dropout Voltage
(0.6V @ 0.5A)
s
750mA Output Current
Capability
s
Externally Programmed
RESET Delay
s
Fault Protection
Reverse Battery
60V Load Dump
-50V Reverse Transient
Short Circuit
Thermal Shutdown
Block Diagram
V
IN
Over Voltage
Shutdown
Package Options
5 Lead TO-220
V
OUT
Pre-
Regulator
Regulated Supply
for Circuit Bias
-
-
+
+
Charge
Current
Generator
Thermal
Shutdown
Latching Discharge
-
Bandgap
Reference
Error Amplifier
Anti-Saturation
and
Current Limit
V
OUT
SENSE
Delay
Q
-
VDISC
S
R
+
Delay Comparator
+
1
2
3
4
5
1
RESET
V
IN
V
OUT
Gnd
Delay
RESET
Gnd
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 2/5/99
1
A
¨
Company
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
