CS8121 Datasheet, PDF (1/8 Pages) Cherry Semiconductor Corporation – 5V, 1A Linear Regulator with and ENABLE RESET

CS8121
5V, 1A Linear Regulator
with _RESET and _ENABLE
Description
Features
The CS8121 is a 5V, 1A precision linear
regulator with two microprocessor
compatible control functions and pro-
tection circuitry included on chip. The
composite NPN-PNP output pass tran-
sistor assures a lower dropout voltage
(1.2V @ 1A) without requiring exces-
sive supply current (4mA).
The CS8121’s two logic control func-
tions make this regulator well suited to
applications requiring microprocessor-
based control at the board or module
level. ENABLE controls the output
stage. A high voltage (>2.9V) on
the ENABLE lead turns off the regula-
tor’s pass transistor and sends the IC
into Sleep mode where it draws only
250µA. RESET sends a RESET signal
when the IC is powering up or when-
ever the output voltage falls out of reg-
ulation. The RESET signal is valid
down to V_OUT = 1V.
The CS8121 design optimizes supply
rejection by switching the internal
bandgap reference from the supply
input to the regulator output as soon as
the nominal output voltage is achieved.
Additional on chip filtering enhances
rejection of high frequency transients
on all external leads.
The CS8121 is fault protected against
short circuit, over voltage and thermal
runaway conditions.
s 5V ± 4% Output Voltage
s Low Dropout Voltage
(1.2V @ 1A)
s Low Quiescent Current
(4mA @ I_OUT = 1A)
s µP Compatible Control
Functions
RESET
ENABLE
s Low Current Sleep Mode
I_Q = 250µA
s Fault Protection
Thermal Shutdown
Short Circuit
60V Peak Transient
Voltage
Block Diagram
Package Options
5 Lead TO-220
V_IN
ENABLE
RESET
ENABLE
Comparator
Over
Voltage
Shutdown
Bandgap
Supply
VREF
Thermal
Shutdown
TO V_OUT
Bandgap
Reference
RESET
Comparator
Output
Current
Limit
- + _Error
Amplifier
December, 2001 - Rev. 7
1
V_OUT
5 Lead
TO-220
V_OUT(SENSE)
Gnd
1 V_IN
2 ^ENABLE
3 Gnd
4 RESET
1
5 V_OUT
7 Lead D²PAK
1
1 NC
2 V_IN
3 ^ENABLE
4 Gnd
5 RESET
6 V_OUT
7 V_OUT(SENSE)
ON Semiconductor
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885–3600 Fax: (401)885–5786
N. American Technical Support: 800-282-9855
Web Site: www.cherry–semi.com