AK4691 Datasheet, PDF (58/80 Pages) Asahi Kasei Microsystems – 4ch ADC + 2ch DAC with MIC/HP/SPK-AMP

[AK4691]
<ALC Operation Example of Speaker Playback>
Register Name Comment
fs=48kHz
Data
Operation
LMTH1-0
Limiter detection Level
00
−2.5dBFS
ZELMN
Limiter zero crossing detection
0
Enable
ZTM1-0
Zero crossing timeout period
10
10.7ms
Recovery waiting period
WTM2-0
*WTM2-0 bits should be the same or 011
21.3ms
larger data to ZTM1-0 bits
REF7-0
Maximum gain at recovery operation C1H
+18dB
IVL7-0,
IVR7-0
Gain of IVOL
91H
0dB
LMAT1-0
Limiter ATT step
00
1 step
RGAIN1-0
Recovery GAIN step
00
1 step
ALC
ALC enable
1
Enable
Table 54. ALC Operation Example of Speaker Playback
<Speaker-Amp Control Sequence>
Speaker-Amp is powered-up/down by PMSPK bit. When PMSPK bit is “0”, both SPP and SPN pin are in Hi-Z state.
When PMSPK bit is “1” and SPPSN bit is “0”, the Speaker-Amp enters power-save mode. In this mode, the SPP pin is
placed in Hi-Z state and the SPN pin outputs SVDD/2 voltage. Power-save mode can reduce pop noise at power-up and
power-down.
PMSPK bit
0
1
SPPSN bit
Mode
SPP pin
SPN pin
x
Power-down
Hi-Z
Hi-Z
0
Power-save
Hi-Z
SVDD/2
1
Normal Operation Normal Operation Normal Operation
Table 55. Speaker-Amp Mode Setting (x: Don’t care)
(default)
PMSPK bit
SPPSN bit
SPP pin
Hi-Z
Hi-Z
SPN pin _Hi-Z ^SVDD/2
SVDD/2
Hi-Z
Figure 39. Power-up/Power-down Timing for Speaker-Amp
■ MUTE Function
When the MUTE pin is “H”, the output signals of LINEOUT, Headphone-Amp, and Speaker-Amp are muted, and
become VCOM or LVCM voltage. LINEOUT and Speaker-Amp become Power-save mode, HP-Amp is in mute state.
And switches of DACL, DACS, DACH, BEEPL, BEEPS, BEEPH, MICL1, MICR1, and MICL2 become “OFF” at the
same time.
MS0672-E-00
- 58 -
2007/11