Package Lead Description
LEAD SYMBOL
PACKAGE LEAD #
20 Lead SOIC
FUNCTION
8 Lead
5 Lead
SOIC (Internally Fused Leads) TO-220
8
1
3
4
19
20
1
5
1
2
3
VIN
Input voltage.
5V, ±2%, 100mA output.
VOUT
ENABLE
Gnd
Logic level switches output off when toggled HIGH.
Ground. All Gnd leads must be connected to Ground.
4,5,6,7
14,15,16,17
RESET
5
2
10
4
Active reset (accurate to VOUT ³ 1V).
VOUTSense
Kelvin connection which allows remote sensing of out-
put voltage for improved regulation. If remote sensing
is not required, connect to VOUT
.
6,7
2,3,8,9,11,12,13,18
NC
No Connection.
Circuit Description
Voltage Reference and Output Circuitry
Output Stage Protection
FOR 7V < V < 26V
IN
The output stage is protected against overvoltage, short
circuit and thermal runaway conditions (Figure 1).
V
IN
ENABLE
V
IN
H
> 30V
VRH
VRL
V
IN
V
OUT
V
OUT
(1)
VR
VR
PEAK
PEAK
(2)
VRLO
RESET
(1) = NO RESET DELAY CAPACITOR
(2) = WITH RESET DELAY CAPACITOR
I
OUT
Load
Dump
Current
Limit
Short
Circuit
Figure 2. Circuit Waveform
ENABLE
The
and OFF. When the voltage on the
1.4V typ, the output pass transistor turns off, leaving a
high impedance facing the load. The IC will remain in
Sleep mode, drawing only 50µA, until the voltage on this
Function
function switches the output transistor ON
ENABLE
Figure 1. Typical Circuit Waveforms for Output Stage Protection.
ENABLE
If the input voltage rises above 30V (e.g. load dump), the out-
put shuts down. This response protects the internal circuitry
and enables the IC to survive unexpected voltage transients.
lead exceeds
Should the junction temperature of the power device exceed
180ûC (typ) the load current capability is reduced thereby
preventing thermal overload. This thermal management
function is an effective means to prevent die overheating
since the load current is the principle heat source in the IC.
ENABLE
input drops below the
threshold.
RESET
Function
RESET
A
signal (low voltage) is generated as the IC pow-
ers up until VOUT is within 250mV of the regulated output
voltage, or when VOUT drops out of regulation,and is
lower than 300mV below the regulated output voltage. A
hysteresis of 50mV is included in the function to minimize
oscillations.
Regulator Control Functions
The CS8101 contains two microprocessor compatible con-
ENABLE
RESET
(Figure 2).
trol functions:
and
RESET
The
output is an open collector NPN transistor,
controlled by a low voltage detection circuit. The circuit is
functionally independent of the rest of the IC thereby
RESET
guaranteeing that the
as 1V.
signal is valid for VOUT as low
3
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
