M54128 Mitsubishi, M54128 Datasheet - Page 7

• Manufacturer Part Number: M54128
• Description: EARTH LEAKAGE CURRENT DETECTOR
• Manufacturer: Mitsubishi

PRECAUTIONS FOR APPLICATION
Note that the improvement examples in the following precautions
for application of M54128FP/L are merely examples.
1. VS applied voltage
2. Resistor of IREF pin (R = 130k )
3. Layout of printed circuit board
4. Be careful that the voltage of SCRT output pin does not
5. Change in sensitivity due to insulation deterioration
Reference constant current source of the lC (for restraining
fluctuations in supply voltage characteristics and ambient
temperature characteristics).
Since this resistor determines the characteristics of each circuit,
use of high-precision resistor ( 2%) is recommended.
External noise (noise simulator etc.) may cause faulty operation
of the lC.
To improve the noise immunity, layout the printed circuit board
so that the wiring of the external C and R is made as short as
possible.
Special attention should be given to the wiring of the condensers
connected to Vs, Vcc and S
(1) ls circuit current (clamp circuit characteristics of the
power supply
(2) Use of the lC by rectifying commercial power supply
(3) lf normal DC power supply is used, use the lC at Vs=7to10V.
become lower than the GND level.
If the insulation of ZCT input pin from the high voltage part might
deteriorate, improvement might be expected by connecting a
resistor of about R=100k
It should be noted that the circuit current will increase at
I
Commercial
=
2.7V/R (approx.).
equivalent circuit) is as shown in TYPlCAL CHARAC-
TERISTICS figure 1 on page 9. Attention should be given to
the circuit current when designing the power supply circuit.
a) As Vz, be sure to use zener diode of 12V or less (not
b) At high temperatures, clamp voltage decreases and ls
exceeding the absolute maximum rating of 15V).
increases. lncrease of ls will be restricted at Rs, however.
between V
CRT
pins.
R
REF
V
S
Z
pin and GND.
V
S
IC
6. Clamp diode of IBLI input pin
As shown in the equivalent circuit, it is made up of series resistor
(approx. 2k ) and seven stages of forward diode.
(1) At high temperatures, the drop in diode V
(2) During excessive input, as shown above, setting should be
Input
the clamp voltage of the pin. If the voltage approaches the
reference level of the comparator (2.4V) and current leaks
occur, the overvoltage detection level may slightly fluctuate.
Form the detection circuit as the figure below. It is
recommended that R
made so that the input pin voltage becomes 4.3V or lower
(to prevent the saturated comparator circuit from operating).
EARTH LEAKAGE CURRENT DETECTOR
• V
MITSUBISHI <CONTROL / DRIVER IC>
Z
=
4.0V
R1
1
R2
, R
2
and V
M54128L/FP
V
Z
Z
be set as shown below.
• R
•
R
R
1
1
1
+ R
+ R
x R
F
2
2
2
may decrease
> 200k
< 7k
I
BLI
pin