RNA51957A, B

Preliminary

REJ03D0912-0402 Rev.4.02

Page 7 of 13

Apr 01, 2010

Example of Application Circuit

Reset Circuit of RNA51957

RNA51957x

RESET

Logic circuit

Input

GND

GND

Delay capacitor

Cd

Power-

supply

Power-

supply

Output

Figure 1 Reset Circuit of RNA51957

When the voltage is anything except 4.25 V, RNA51957 and RNA51958 are used. In this case, the detecting

supply voltage is 1.25

 (R

The detecting supply voltage can be set between 2 V and 15 V.

2. If a longer delay time is necessary, RNA51953, RNA51957, RNA51958 are used. In this case, the delay

time is about 0.34

 Cd (pF) s.

3. If the RNA51957 and the logic circuit share a common power source, type A (built-in load type) can be used

whether a pull-up resistor is included in the logic circuit or not.

overcome the pull-down resistor.

5. When the reset terminal in the logic circuit is of the low reset type, RNA51953 and RNA51957 are used and

when the terminal is of the high reset type, RNA51958 are used.

6. When a negative supply voltage is used, the supply voltage side of RNA51957 and the GND side are

connected to negative supply voltage respectively.

Case of Using Reset Signal except Supply Voltage in the RNA51957

(a) Reset at ON

(b) Reset at transistor ON

Input

RESET

Logic circuit

Input

GND

Delay capacitor

GND

Cd

RESET

Logic circuit

GND

Delay capacitor

GND

Cd

Out

put

Out

put

RNA51957x

RNA51957x

Control

signal

Power-

supply

Power-

supply

Power-

supply

Power-

supply

Figure 2 Case of Using Reset Signal except Supply Voltage in the RNA51957