M54133FP Просмотр технического описания (PDF) - MITSUBISHI ELECTRIC
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M54133FP Datasheet PDF : 12 Pages
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MITSUBISHI <CONTROL / DRIVER IC>
M54133FP/GP
EARTH LEAKAGE CURRENT DETECTOR
PRECAUTION FOR APPLICATION
Described below are precautions on usage of the M54133FP and
the M54133GP. Note that each precaution presents a still better
example. It is advisable to review it carefully to learn optimal
conditions.
1. Voltage applied to VS
1. Fig.1 shows characteristics of circuit current IS.
(IS characterizes clamp circuit shown in INPUT/OUTPUT
equivalent circuits.) To design power supply, adapt it to IC,
considering IS characteristics.
2. Rectification for use of commercial AC line as power source.
3. Laying out printed-circuit board
Foreign noise (from noise simulator, for example) may cause
malfunctions.
To improve noise resistance, lay out printed-circuit patterns so that
wirings of IC to additional capacitors and resistors can be made as
short as possible.
Carefully design patterns especially for wiring capacitors to VS of
pin 16 , VCC of pin 3 , and SCRT of pin 8 .
4. Avoid SCRT output pin voltage from falling negative
below GND level.
COMMERCIAL
AC LINE
5. Reset time applicable to reset timer circuit
RS
The M54133 has reset timer circuit of VL=0.7V, VH=2.4V, and
VS
IO=7.5µA. When SCR is on, power supply path is disconnected
VZ
IC
from leak detector circuit. As shown in illustration below,
disconnection may inhibit VL from falling to 0.7V. Accordingly, reset
time may get shortened. To avoid shortage, predetermine a reset
time that includes extra time.
3
IS
(mA) 2
1
+85°C
+25°C
-20°C
0
12 13 14 15
VS(V)
Fig. 1 CHARACTERISTICS OF VS TO IS
a) For VZ, select zener diode of 12V or less. (Prevent supply
voltage VS from exceeding absolute maximum rating of 15V.)
b).Escalated temperature may decrease supply voltage to
produce large current IS. In this case, RS limits IS.
3. For use of common DC power supply, set supply voltage VS
within range of 7 to 12V.
T= CX(VH-VL) = 0.33µFX(2.4-0.7) =75ms
IO
7.5µA
WAVEFORMS
AT
OFFC PIN
2.4V
WAVEFORMS
AT
SCRT PIN
0V
75ms
3.8V
0.7V
t=10ms
Note. Predetermined reset time may get shortened by t.
2. Resistor (R=180kΩ) at IREF pin
This resistor provides constant-reference-current source for IC.
(Constant current source protects IC against fluctuations in supply
voltage and ambient temperature.)
Since every circuit is characterized by resistance of this resistor,
the use of high-precision resistor (accuracy of ±2%) is
recommended.
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