ak4516a AKM Semiconductor, Inc., ak4516a Datasheet - Page 32

• Manufacturer Part Number: ak4516a
• Description: 3v 16bit Adc&dac With Built-in Pga
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
Auto Recovery Control
M0026-E-00
Addr
0CH Auto Recovery Control 1
WTM1-0: Auto Recovery Waiting Time
RATT1-0: Auto Recovery GAIN Step
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 )
Register Name
RESET
WTM1
R/W
0
0
1
1
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.
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.
WTM0
Table 12 . Auto Recovery Operation Waiting Period
RATT1
0
1
0
1
Table 13 . Auto Recovery GAIN Step Setting
0
0
1
1
RD
D7
0
0
1024/fs
2048/fs
4096/fs
512/fs
RATT0
0
1
0
1
RD
D6
0
0
- 32 -
GAIN STEP
10.7ms
21.3ms
42.6ms
85.2ms
48kHz
RD
D5
0
0
1
2
3
4
Timeout
RD
D4
0
0
44.1kHz
11.6ms
23.2ms
46.4ms
92.8ms
RESET
WTM1 WTM0 RATT1 RATT0
R/W
D3
1
128.0ms
16.0ms
32.0ms
64.0ms
32kHz
R/W
D2
0
RESET
R/W
D1
0
[AK4516A]
1998/08
R/W
D0
0