Adjustable Shunt Regulator
Wide operating current range 130μA to 150mA
Low dynamic output impedance 0.25Ω typ.
Trimmed bandgap + 0.5%
Alternate for TL1431, TL431, LM431& AS431
Military temperature range
Available in SOT-23-3 package, fully WEEE and RoHS
Switching Power Supplies
Typical Application Circuit
The SC431M is a three terminal adjustable shunt regulator
with thermal stability guaranteed over temperature. The
output voltage can be adjusted to any value from 2.5V (VREF) to
30V with two external resistors.
The SC431M has a typical dynamic output impedance of
0.25Ω. Active output circuitry provides a very sharp turn on
characteristic, making the SC431M an excellent replacement
for Zener diodes.
The SC431M shunt regulator is available with a 0.5% voltage
tolerance over TA = -55°C to +125°C and comes in a SOT-23-3
1) Set VOUT according to the following equation:
2) Choose the value for R as follows:
The maximum limit for R should be such that the
cathode current, IZ, is greater than the minimum
operating current (130μA) at VIN(MIN).
The minimum limit for R should be such that IZ does
not exceed 150mA under all load conditions, and the
instantaneous turn-on value for IZ does not exceed
200mA. Both of the following conditions must be met:
(to limit instantaneous turn-on IZ)
(to limit IZ under normal operating conditions)
August 1, 2017
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