MITSUBISHI
M54122L
EARTH LEAKAGE CURRENT DETECTOR
DESCRIPTION
The M54122L is a semiconductor integrated circuit with amplifier for a high-speed earth leakage circuit breaker.
PIN CONFIGURATION (TOP VIEW)
FEATURES
q Suitable for JIS C 8371 q Good temperature characteristics of input sensitivity current q High input sensitivity (VT = 13. 5mV Typ. ) q Low external component count q High noise and surge-proof q Low power dissipation (Pd = 5mW Typ. ) and may be used both as 100V and 200V. q High mounting density by SIL package with 8 pins q Wide temperature range (Ta = -20 – +80°C)
Reference voltage Input
VR → IN → GND
1 2 3 4 5 6 7 8 REG
LATCH
AMP
Differential amplifier output Latch input Terminal for noise absorption Output
OD ← SC → NR → OS ← VS
APPLICATION
High speed earth leakage circuit breaker
FUNCTION
The M54122L circuit for the amplifying parts of earth leakage circuit breaker consists of differential amplifier, latch circuit and voltage regulator. It is connected to the secondary side of the zerocurrent transformer (ZCT) which detects leakage current in the both input of the differential amplifier. Signals amplified by differential amplifier are integrated by an external capacitor, and connects to the input terminal of latch circuit with output suitable for the characteristics of high-speed earth leakage circuit breaker. Latch circuit keeps low in the output till the input voltage reaches the fixed level, and output becomes high when the leakage current more than fixed flows. It drives a thyristor connected to the output terminal of latch circuit. Outline 8P5
BLOCK DIAGRAM
VS 8 Reference voltage generation circuit
Latch circuit
AMP
7
OS output
GND 3
1 VR Reference voltage
2 IN Input
4 OD Differential amplifier output
5 SC Latch input
6 NR Terminal for noise absorption
BIAS
MITSUBISHI
M54122L
EARTH LEAKAGE CURRENT DETECTOR ABSOLUTE MAXIMUM RATINGS (Ta = -20 – 80°C unless otherwise noted)
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M54122L PDF File
