BM28723AMUV
Description of Function - continued
3
PWM Sampling Frequency
PWM sampling frequency of speaker output, Soft mute time, Soft start time and PWM stop time depend on sampling
frequency (fS) of the digital audio signal. These transition times are changed by sending the data to select address 0x15[1:0].
Default=0x3
Sampling
PWM Sampling
Frequency
0x15[1:0]
Value
Soft Mute
Time
Soft Start
Time
PWM Stop
Time
frequency (fS)
0x0
0x1
0x2
0x3
0x0
0x1
0x2
0x3
0x0
0x1
0x2
0x3
10.7ms
21.4ms
42.7ms
85.4ms
11.7ms
23.3ms
46.5ms
92.9ms
16.1ms
32.1ms
64.1ms
128.1ms
10.7ms
10.7ms
10.7ms
10.7ms
11.7ms
11.7ms
11.7ms
11.7ms
16.1ms
16.1ms
16.1ms
16.1ms
86ms
106ms
125ms
162ms
93ms
48kHz
384kHz
352.8kHz
256kHz
113ms
135ms
177ms
116ms
148ms
178ms
241ms
44.1kHz
32 kHz
4
Setting Driver Gain (GDRV
)
It can change the driver gain of the output FET driver part.
Set it depending on speaker used because the maximum output level changes by speaker load impedance value.
When set the driver gain, change after setting MUTEX pin to Low (>PWM stop time).
Pop noise may be occurred if the driver gain is set while MUTEX=High.
Default=0x03
Driver Gain
Select Address
Value
GDRV (BTL)
26dB (Typ)
32dB (Typ)
0xF3[7:0]
0xF3[7:0]
0x03
0x0B
Regarding 0xF3 address,
Prohibit to set except data 0x03 and 0x0B to address 0xF3.
The setting value is fixed by transmitting 0xF8=0x01. If the setting value of address 0xF3 is changed, certainly set
0xF8=0x01 again. In addition, wait time more than 10ms is necessary after 0xF8=0x01 setting.
5
Setting of When Monaural output
When monaural output setting is applied as shown in Application Circuit Example3, set 0xF2 register during start-up (Refer
to P.62 “20. The wake-up Procedure of power-up”).
Setting 0xF2=0x0A, DC voltage protection function at the speaker of OUT2 side can be disabled, therefore it is possible to
use Application Circuit Example3.
Default=0x02
Select Address
0xF2[7:0]
Value
0x02
0x0A
PWM Output
Stereo
Monaural
0xF2[7:0]
Regarding 0xF2 address,
Prohibit to set except data 0x02 and 0x0A to address 0xF2.
The setting value is fixed by transmitting 0xF8=0x01. If the setting value of address 0xF2 is changed, certainly set
0xF8=0x01 again. In addition, wait time more than 10ms is necessary after 0xF8=0x01 setting.
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TSZ02201-0C1C0E900720-1-2
31.Aug.2018 Rev.001
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