M54128FP データシートの表示（PDF） - Mitsumi

部品番号

コンポーネント説明

メーカー

M54128FP

EARTH LEAKAGE CURRENT DETECTOR

Mitsumi 

MITSUBISHI <CONTROL / DRIVER IC>

M54128L/FP

EARTH LEAKAGE CURRENT DETECTOR

PRECAUTIONS FOR APPLICATION

Note that the improvement examples in the following precautions

for application of M54128FP/L are merely examples.

1. VS applied voltage

(1) ls circuit current (clamp circuit characteristics of the

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.

6. Clamp diode of IBLI input pin

As shown in the equivalent circuit, it is made up of series resistor

(approx. 2kΩ) and seven stages of forward diode.

(1) At high temperatures, the drop in diode VF may decrease

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 R1, R2 and VZ be set as shown below.

Commercial

power supply

RS

VS

R1

IC

Input

VZ

IBLI pin

R2

VZ

(2) Use of the lC by rectifying commercial power supply

a) As Vz, be sure to use zener diode of 12V or less (not

exceeding the absolute maximum rating of 15V).

b) At high temperatures, clamp voltage decreases and ls

increases. lncrease of ls will be restricted at Rs, however.

(3) lf normal DC power supply is used, use the lC at Vs=7to10V.

2. Resistor of IREF pin (R = 130kΩ)

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.

3. Layout of printed circuit board

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 SCRT pins.

4. Be careful that the voltage of SCRT output pin does not

become lower than the GND level.

5. Change in sensitivity due to insulation deterioration

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=100kΩ between VREF pin and GND.

It should be noted that the circuit current will increase at

I = 2.7V/R (approx.).

• R1 + R2 > 200kΩ

•

R1 x R2

R1 + R2

< 7kΩ

(2) During excessive input, as shown above, setting should be

made so that the input pin voltage becomes 4.3V or lower

(to prevent the saturated comparator circuit from operating).

• VZ = 4.0V

Share Link: