MITSUBISHI
M54124L
EARTH LEAKAGE CURRENT DETECTOR
DESCRIPTION
The M54124L is a semiconductor integrated circuit consisting of an amplifier for a high-speed earth-leakage circuit breaker.
PIN CONFIGURATION (TOP VIEW)
FEATURES
q Satisfies JIS C 8371 q Temperature-stable input current threshold q High-input sensitivity (VT = 6. 5mV) q Low external component count q Highly resistant to noise and power surges q Low power dissipation (Pd = 5mW typ) q Can be used at 100V and 200V q High-density mounting eight-pin SIL package q Wide operating temperature range (Ta = -20 – +80°C)
Reference voltage Input VR ← 1 IN → 2 GND Differential amplifier output One shot multivibrator A One shot multivibrator B Output 3
M54124L
OD ← 4 MA → 5
→ 6 MB ←
OS ← 7 VS 8
APPLICATION
High-speed earth-leakage circuit breakers
Outline 8P5
FUNCTION
The M54124L is a semiconductor integrated circuit for use in the amplifier section of earth-leakage circuit breakers. It consists of a differential amplifier, one-shot circuit, output circuit and voltage regulator. It is connected to the secondary side of the zero-current transformer, ZCT, and detects leakage current in both inputs of the differential amplifier. Signals amplified by the differential amplifier are integrated by an external capacitor, and applied to the input pin of a one-shot multivibrator circuit having time-delay characteristics that are suitable for high-speed earth-leakage circuit breakers (such as specified in JIS C 8371). The one-shot multivibrator circuit normally maintains a low output. When the input current (earthleakage) exceeds a specified level, a one-shot high pulse is output to turn on an externally connected thyristor.
BLOCK DIAGRAM
VCC Output circuit VR
VR Regulator 7 OS Output
1 0
One shot multivibrator A
1
One shot multivibrator B
1
0 Comparator
0
1 2 VR IN Reference Input voltage
3 GND
4 5 OD MA Differential One shot amplifier multivibrator A output
6 MB One shot multivibrato...
M54124L PDF File
