MITSUBISHI <CONTROL / DRIVER IC> 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 Reference voltage Input VR ← 1 IN → 2 3 GND Differential amplifier output OD ← 4 One shot multivibrator A MA → 5 One shot multivibrator B → 6 MB ← Output OS ← 7 APPLICATION M54124L ● Satisfies JIS C 8371 ● Temperature-stable input current threshold ● High-input sensitivity (VT = 6.5mV) ● Low external component count ● Highly resistant to noise and power surges ● Low power dissipation (Pd = 5mW typ) ● Can be used at 100V and 200V ● High-density mounting eight-pin SIL package ● Wide operating temperature range (Ta = -20 – +80°C) 8 VS 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 1 1 0 VR Regulator Output circuit VR 1 One shot multivibrator A One shot multivibrator B 0 0 Comparator 1 2 VR IN Reference Input voltage 3 GND 4 5 OD MA Differential One shot amplifier multivibrator A output 6 MB One shot multivibrator B 7 OS Output 8 VS MITSUBISHI <CONTROL / DRIVER IC> M54124L EARTH LEAKAGE CURRENT DETECTOR OPERATION Discussion refers to the block diagram, application example, and operational waveform diagram. • When an earth leakage current appears on the primary side of zero-current transformer ZCT, leakage signal voltage VIN appears on the secondary side and is input at IN with VR as the reference. • In the half cycle when VIN is negative, capacitor CMA connected to pin MA charges until V IN reaches the trip voltage VT (DC). If voltage VMA at pin MA does not reach the MA threshold voltage, capacitor CMA discharges immediately at a current greater than the charge current, when the charging current phase is completed. When VMA reaches the MA threshold voltage, capacitor CMA discharges at a small current for a period time tCO during which the output of one-shot multivibrator A is high. • During tCO, the same operation takes place again at capacitor CMB, causing one-shot multivibrator B to trigger current pulse of duration tOS at output pin OS. • Earth leakage currents are detected when the amplitude of input voltage VIN exceeds the trip voltage VT (DC) for longer than the input detection time tMA. • The output current is used to turn on the thyristor that opens the breaker contacts. OPERATING WAVEFORM DIAGRAM Earth leakage signal VIN IN VR VR VT(DC) Comparator 1 output H L MA “ON” voltage OD MA “OFF” voltage VMA MA 0 One-shot A1 output H L tMA ∗ (3ms) tCO∗ (65ms) MB “ON” voltage MB “OFF” voltage VMB MB 0 OS 0 VOS tMB ∗ (3ms) tOS∗ (95ms) ∗ tMA tCO tMB tOS : MA input detection time : MA detector on time : MB input detection time : OS output pulse width (MB detector on time) Note. The values in the parentheses are typical values for reference only. MITSUBISHI <CONTROL / DRIVER IC> M54124L EARTH LEAKAGE CURRENT DETECTOR ABSOLUTE MAXIMUM RATINGS (Ta = -20 – 80°C unless otherwise noted) Parameter Symbol Conditions Supply voltage Supply surge current Input current IS IS (SG) IIN IIG Input pin current VOD IMA VOS Pd Topr Tstg OD applied voltage MA input current OS applied voltage Power dissipation Operating temperature Storage temperature Note 1: The surge waveform (Note 1) Between IN and VR (Note 2) Ratings Unit 8 12 -250 – +250 mA mA mA 30 mA 6 4 V mA V mW °C °C Between VR and GND, and between IN and GND When external voltage is applied When external voltage is applied When external voltage is applied 6 200 -20 – 80 -55 – 125 The waveform of surge current IS(SG) is shown on the left. It is applied less than once per minute. 100% IS(SG) 50% 0mA 1µs 40µs Note 2: Applies to currents between IN and VR with pulse widths less than 1ms and duty cycles less than 12%. If AC current is applied, the current limit is 100mArms when the IC supply power is off. Remark: Circuit voltage at GND pin is 0V. Current flowing into the circuit is positive (no sign) and the current flowing out from the circuit is negative (negative sign), unless otherwise noted. Maximum values of rated and specified values are shown in absolute values. RECOMMENDED OPERATING CONDITIONS (Ta = -20 – 80°C unless otherwise noted) Symbol VS CVS COS CMA CMB RIN Parameter Supply voltage when output is OFF Capacitance between VS and GND Capacitance between OS and GND Capacitance between MA and GND Capacitance between MB and GND External resistor at IN Min. 12 Limits Typ. Max. 1 1 0.1 0.1 100 Unit V µF µF µF µF Ω ELECTRICAL CHARACTERISTICS (Ta = -20 – 80°C unless otherwise noted) Symbol Parameter Test conditions IS VT IODL IODH VMAH VMAL IMBL IMBH IOSL Supply current Trip voltage OD sink current OD source current MA “ON” voltage MA “OFF” voltage MB sink current MB source current OS sink current VS = 12V, VIN = -15mV VS = 16V, VIN: 60Hz sine wave VS = 16V, VIN = 0mV, VOD = 4V VS = 16V, VIN = -15mV, VOD = 4V VS = 16V, VIN = -15mA VS = 16V, VIN = -15mA VS = 16V, VIN = 0mA, VMB = 1.6V VS = 16V, VIN = -15mA, VMB = 1.6V VS = 16V, VIN = 0mA, VOS = 0.2V IOSH OS source current VS = 12V, VIN = -15mA, VOS = 1.6V VSM VINC VRCL tMA tCO tMB tOS VS maximum current voltage IN, VR input clamp voltage VR clamp voltage MA input detection time MA detector on time MB input detection time OS input detection time IS = 7mA VS : open, IIN = ±100mA VS = 16V, IVR = 20mA VS = 16V VS = 16V VS = 16V VS = 16V Note: VIN, is the input voltage with VR as reference. VIN is applied to IN through resistor RIN. Temperature (°C) 25 25 25 25 25 25 -20 +25 +80 25 25 25 Test circuit 1 2 3 3 4 4 5 5 6 6 7 9 9 10 10 11 11 Min. 4 120 -75 2.8 0.8 120 -75 200 -200 -100 -75 20 ±0.4 4.4 1.7 40 1.7 60 Limits Typ. Max. 800 9 240 -150 3.4 1.2 240 -150 Unit µA mVrms µA µA V V µA µA µA µA 30 ±2.0 6.6 4.0 100 4.0 150 V V V ms ms ms ms MITSUBISHI <CONTROL / DRIVER IC> M54124L EARTH LEAKAGE CURRENT DETECTOR TEST CIRCUIT (CMA = 0.1µF, CMB = 0.1µF, RIN = 100Ω, Diode are equivalent to MD234, unless otherwise noted) 1 2 3 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 VIN RIN VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 VIN CMB VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 CMA CMB RIN VIN RIN CMB VS VS VOS IS A A VOD VS 4 5 IODH 6 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 VIN IODL ∗ VT is the value of VIN at which OS turns on (VOS > 0.4V) as VIN is increased gradually. VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 RIN VIN VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 CMA RIN VIN VS RIN CMA CMB VS VS VMB VMA A VMAH VMB A IMBL IMBH VOS IOSL IOSH VMAL VMA VMB 0.4V 7 9 8 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 CMA CMB RIN RIN CMA CMB VS V VSM IS 10 V VINC IIN IVR IIN 11 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 VR IN GND OD MA MB OS VS 1 2 3 4 5 6 7 8 CMA RIN CMA CMB RIN VS VIN VS VOS VIN VMB ∗tMB = tMB' -tMA VIN VIN 1.85V 1.85V 1.45V 1.45V VMB tCO tMA 0.4V 0.4V VOS tOS tMB' V VRCL MITSUBISHI <CONTROL / DRIVER IC> M54124L EARTH LEAKAGE CURRENT DETECTOR TYPICAL CHARACTERISTICS MA input detection time vs. ambient temperature Trip voltage vs. ambient temperature 8 MA input detection time tMA (ms) 16 Trip voltage VT (mvrms) 14 12 10 8 6 4 2 0 -50 -25 0 25 50 75 7 6 5 4 3 2 1 0 -50 100 125 150 -25 MA continuous detection time vs. ambient temperature OS output pulse width tSO (ms) MA detector on time tCO (ms) 75 100 125 150 160 140 120 100 80 60 40 20 -25 0 25 50 75 140 120 100 80 60 40 20 0 -50 100 125 150 Ambient temperature Ta (°C) -25 0 25 -400 Operating time tD (ms) -350 -250 -200 -150 -100 -50 75 100 125 150 Operating time vs. input voltage 1000 700 500 300 -300 50 Ambient temperature Ta (°C) OS source current vs. ambient temperature OS source current IOSH (µA) 50 OS output pulse width vs. ambient temperature 160 0 -50 25 Ambient temperature Ta (°C) Ambient temperature Ta (°C) 0 -50 0 Ta = 25°C 60HZ 100 70 50 30 10 7 5 3 1 -25 0 25 50 75 100 125 150 Ambient temperature Ta (°C) 1 3 5 7 10 30 50 100 70 500 1000 300 Input voltage VI (mVrms) MITSUBISHI <CONTROL / DRIVER IC> M54124L EARTH LEAKAGE CURRENT DETECTOR APPLICATION EXAMPLE • A high-speed earth-leakage circuit breaker using the M54124L Power supply M54124L VR 1 IN 2 GND 3 OD 4 MA 5 MB 6 OS 7 VS 8 RIN 100Ω CMA 0.1µF Note 3 ZCT CMB 0.1µF CVS 1µF COS 1µF Load Note 3 : MZ Core Series by Soryo Denshi Kagaku Co., Ltd (Mitsubishi Subsidiary) Tel. +81-427-74-7813