AK4951AEN Datasheet, PDF (59/105 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/HP/SPK-AMP

[AK4951A]
■ BEEP Input
When BEEPS bit is set to “1” during PMBP = PMSL = SPLSN bits = “1”, the input signal from the
RIN3/BEEP pin is output to the speaker-amp (LOSEL bit = “0”) or stereo line output (LOSEL bit = “1”).
When BEEPH bit is set to “1” during PMHPL or PMHPR bit = “1”, the input signal from the RIN3/BEEP pin
is output to the stereo headphone amplifier. BPLVL3-0 bits set the gain of BEEP-Amp, and the total gain
is defined according to SPKG1-0 bits setting. When the BEEP signal is output to the stereo headphone
amplifier, AK4951A operates without the system clock. In order to operate the charge pump circuit, it is
necessary to power up the internal oscillator (PMOSC bit = “1”).
When PMDAC bit = “1” and PMHPL bit or PMHPR bit = “1”, switching noise of connection between the
BEEP generating circuit and headphone amplifier can be suppressed by soft transition. The transition
time of ON/OFF switching is set by PTS1-0 bits. Soft transition Enable/Disable is controlled by MOFF bit.
When this bit is “1”, soft transition is disabled and the headphone is switched ON/OFF immediately.
PTS1
bit
0
0
1
1
Table 52. BEEP ON/OFF Transition Time (MOFF bit = “0”)
PTS0
ON/OFF Time
bit
8kHz ≤ fs ≤ 24kHz
24kHz < fs ≤ 48kHz
0
64/fs
2.7~8ms
128/fs 2.7~5.3ms
1 128/fs 5.3~16ms 256/fs 5.3~10.7ms (default)
0 256/fs 10.7~32ms 512/fs 10.7~21.3ms
1 512/fs 21.3~64ms 1024/fs 21.3~42.7ms
BPVCM bit set the common voltage of BEEP input amplifier (Table 53).
Table 53. Common Potential Setting of BEEP-Amp
BPVCM bit BEEP-Amp Common Voltage (typ)
0
1.15V
(default)
1
1.65V (Note 14, Note 40)
Note 14.The maximum value is AVDD Vpp when BPVCM bit = “1”. However, a click noise may occur
when the amplitude after BEEP-Amp is 0.5Vpp or more. (set by BPLVL3-0 bits)
Note 40. When the BEEP signal is output to the speaker amplifier and BPVCM bit = “1”, SVDD must be
supplied 2.8V or more.
Input BEEP gain is controlled by BPLVL3-0 bits (Table 54).
Table 54. BEEP Output Gain Setting
BPLVL3 bit BPLVL2 bit BPLVL1 bit BPLVL0 bit BEEP Gain
0
0
0
0
0dB
0
0
0
1
6dB
0
0
1
0
12dB
0
0
1
1
18dB
0
1
0
0
24dB
0
1
0
1
30dB
0
1
1
0
33dB
0
1
1
1
36dB
1
0
0
0
39dB
1
0
0
1
42dB
Others
N/A
(N/A: Not available)
(default)
016001936-E-00
- 59 -
2016/03