AK7841 Datasheet, PDF (8/21 Pages) Asahi Kasei Microsystems – Monaural Audio Class-D Amp with Power Booster for PiezoSpeaker

ASAHI KASEI
AKM CONFIDENTIAL
[AK7840]
OPERATION OVERVIEW
„ Power Control
The AK7841 enters shutdown mode by setting “PDN” pin to Logic “Low” level.
And resumes normal operation mode (Stability Operation) by setting “PDN” pin to Logic “High” level.
Power-Up Control
VBAT and DVDDI must be turned on as (1) or (2) below.
(1) VBAT=DVDDI=”ON” simultaneously.
(2) VBAT=”ON” first, then DVDDI=”ON”.
Set PDN pin to “High” when driving AK7841. Then, 1µs wait after VBAT=DVDDI=”High” is necessary
before setting PDN=”High”. Do not do them simultaneously.
VBAT “ON” _0V
DVDDI “ON” _0V
> 1us
PDN pin
0V
Figure. 3 Power-Up Sequence (1)
VBAT “ON” _0V
>0
DVDDI “ON” _00VV
> 1us
PDN pin
0V
Figure. 4 Power –Up Sequence (2)
Attention: The performance of the device will not be guaranteed after the below sequence.
(3) DVDDI=”ON” first, then VBAT=”ON”.
Rev.08
2008/3
-8-