SM6801A Datasheet, PDF (9/16 Pages) Nippon Precision Circuits Inc – Class-D Mono Amplifier for Portable Device

SM6801A
FUNCTIONAL DESCRIPTION
Power-down (PDWN)
The device enters power-down mode when PDWN goes LOW. When powered-down, the outputs become high
impedance and the internal oscillation stops. In power-down mode, the MUTEN pin should be held LOW.
Mute (MUTEN)
Mute operation occurs when MUTEN goes LOW. In mute mode, the outputs become high impedance. During
mute operation, the protection circuit operation is disabled, but the outputs are protected against output short
circuits by their high impedance state. When power is applied, MUTEN should be held LOW for a short inter-
val, shown in the timing diagram below, to prevent pop noise from the speaker. Also, applying and releasing
mute operation after power is applied can occur at high speed without generating pop noise.
PDWN
MUTEN
min. 40msec
Note. VREF1 load capacitance = 1µF
Protection Circuit
The protection circuit operates if there is an output short-circuit to the supply, short-circuit to ground, or other
excessive load abnormal condition lasting longer than approximately 1µs. Normal operation resumes after
approximately 5 seconds. When the protection circuit becomes active, the outputs become high impedance.
The usage with direct coupling to load is recommended for operating VDD1, VDD2, VDD3 and VDD4 at
≤ 2.4V. When using LC-type LPF, the ringing phenomena due to rush current may be judged as short-circuit of
the load. In this case, the normal operation will start after the mute for 5 seconds.
SEIKO NPC CORPORATION —9