AK4516AVF View Datasheet(PDF) - Asahi Kasei Microdevices
Part Name
Description
MFG CO.
'AK4516AVF' PDF : 39 Pages View PDF
ASAHI KASEI
[AK4516A]
Auto Recovery Control
Auto recovery operation starts after completing auto limitter operation (LCDET="1") at LMTE=RCVE="1".
IPGA gain increases automatically by this operation up to the set reference level(REF6-0). Then the IPGA
value is set for L/R commonly. Either zero crossing or fs(sampling frequency) period for this auto recovery
operation is decided by zero crossing detection at the auto recovery operation and the writing operation by
uP (=ZENM).
During the auto recovery operation, when either input signal level of Lch or Rch exceeds the auto limitter
detection level (LMTH1-0), the auto recovery operation changes into the auto limitter operation immediately.
(Refer to Figure 9 )
Addr Register Name
D7
D6
D5
D4
D3
D2
D1
D0
0CH Auto Recovery Control 1
0
0
0
0 WTM1 WTM0 RATT1 RATT0
R/W
RD RD RD RD R/W R/W R/W R/W
RESET
0
0
0
0
1
0
0
0
WTM1-0: Auto Recovery Waiting Time
Recovery operation is done at a period set by WTM1-0 when any limitter operation does not
occur at full-auto mode. When the input signal level exceeds auto recovery waiting counter
reset level set by LMTH1-0, the auto recovery waiting counter is reset.
The waiting timer starts when the input signal level becomes below the auto recovery waiting
counter reset level.
When the auto recovery waiting time(WTM1-0) is shorter than zero crossing timeout period
of the auto recovery operation(NRTM1-0), the auto recovery is operated by NRTM1-0.
Therefore, in this case the auto recovery operation period is not constant.
WTM1
0
0
1
1
WTM0
Timeout
48kHz 44.1kHz
32kHz
0
512/fs
10.7ms 11.6ms 16.0ms
1
1024/fs
21.3ms 23.2ms 32.0ms
0
2048/fs
42.6ms 46.4ms 64.0ms
1
4096/fs
85.2ms 92.8ms 128.0ms
Table 12 . Auto Recovery Operation Waiting Period
RESET
RATT1-0: Auto Recovery GAIN Step
During the auto recovery operation, the number of steps changed from current IPGA value is
set. For example, when the current IPGA value is 30H, RATT1="0", RATT0="1" are set, IPGA
changes to 32H by the auto limitter operation, the input signal level is gained by 1dB(=0.5dB
x 2).
The auto recovery operation period is fs period at ZENM="0", the auto recovery operation is
done after zero crossing detection or timeout in case of ZENM="1"
When the IPGA value exceeds the reference level (REF6-0), the IPGA value does not
increase.
RATT1
RATT0 GAIN STEP
0
0
1
RESET
0
1
2
1
0
3
1
1
4
Table 13 . Auto Recovery GAIN Step Setting
M0026-E-00
- 32 -
1998/08
Share Link: 
