M54123L

DESCRIPTION 

The UTC M54123L is a semiconductor integrated circuit with 

amplifier for a high-speed earth leakage circuit breaker. 

For the amplifying parts of earth leakage circuit breaker, the 

UTC M54123L consists of differential amplifier, latch circuit and 

voltage regulator. 

In normal operating, the UTC M54123L should be connected to 

the secondary side of the ZCT (zero current transformers). Here 

the ZCT detects leakage current different amplifiers’ both input. 

Then the signals which have been amplified are integrated by 

an external capacitor. The integrated signal connects to the input 

terminal of latch circuit whose output is suitable for the 

characteristics of high- speed earth leakage circuit breaker. 

Until the input voltage reaches the fixed level, latch circuit 

doesn’t become high. Then drives a thyristor which is connected to 

latch circuit’s output terminal. Once the trigger latch circuit, only the 

power on again to reset. 

FEATURES 

* With good input sensitivity current temperature characteristics 

* High input sensitivity :VT=6.1mV (Typ.) 

* Only need low external component count 

* High noise and surge-proof 

* Low power dissipation :PD=5mW (Typ.) 

* May be used both as 100V and 200V. 

* Wide temperature range : from -20 °C to +80°C 

规格书M54123L