M61558FP

Rev.1.0, Sep.19.2003, page 16 of 17

Muting operation by force

The output is forcibly muted by using a resistor to pull the PRLPFVD pin (pin 19) down to ground (signal output is

terminated and the output terminals enter the Hi-Z open state; refer to the figure below). To cancel muting, release pin

19 from the pulled-down state, and then input a cancellation pulse on the EN pin (pin 25) in the same way as is used to

cancel the protection state.

Please note the following points:

• Muted operation is only possible during normal operation; that is, it is not possible in transient states, such as while

turning the power supply on or off.

• For actual usage, please thoroughly evaluate and examine the forcible mute operation.

Note: The above setting assures operation by ensuring the flow of

a strong current. Decreasing the resistance below this level

has no effect.

M61558FP

Mute circuit

R = 4.2 k

Ω (see note)

19