CS8120
Typical Performance Characteristics: continued
Quiescent Current vs. Output Current Over Temperature
3.5
V
IN
= 14V
3.0
-40°C
Output Voltage and Supply Current vs. Input Voltage
5.5
5.0
V
OUT
22.0
20.0
Quiescent Current (mA)
2.0
125°C
1.5
V
OUT
(V)
25°C
3.0
I
Q
2.0
12.0
8.0
1.0
1.0
0.5
4.0
0.0
0
50
100
150
200
250
300
350
0.0
0.0
2.0
Output Current (mA)
0.0
4.0
6.0
Supply Voltage (V)
8.0
10.0
RESET Output Voltage vs. Output Current
2000
1800
Reset Output Voltage (mV)
1600
1400
1200
1000
800
600
400
200
0
1
5
V
IN
= 5V
10
15
20
25
30
35
40
Reset Output Current (mA)
Circuit Description
Voltage Reference and Output Circuitry
Precision Voltage Reference
The regulated output voltage depends on the precision
band gap voltage reference in the IC. By adding an error
amplifier into the feedback loop , the output voltage is
maintained within ±4% over temperature and supply
variation.
Output Stage
V
IN
The NPN pass device prevents deep saturation of the out-
put stage which in turn improves the ICÕs efficiency by
preventing excess current from being used and dissipated
by the IC.
Output Stage Protection
The output stage is protected against overvoltage, short
circuit and thermal runaway conditions (Figure 2).
> 30V
The composite PNP-
NPN output structure
(Figure 1) provides
300mA (typ) of output
current while maintain-
ing a low drop out volt-
age (1.00V, typ) and
drawing little quiescent
current (2.5mA).
V
OUT
V
IN
V
OUT
I
OUT
Figure 1: Composite Output Stage of the CS8120
Load
Dump
Short
Circuit
Thermal
Shutdown
Figure 2: Typical Circuit Waveforms for Output Stage Protection.
4
Supply Current (mA)
2.5
4.0
16.0
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
