BU26156RFS Datasheet, PDF (32/95 Pages) Rohm – Monoraul MIC Input with ALC

BU26156RFS
Datasheet
Analog block
Analog Reference Voltage (VMID) Generation Circuit
VMID is used as analog circuit reference voltage for both recording path and playback path. Therefore, both case for
recording and playback, VMID need to do power up. At the power up, the wait time in proportion to the capacitor value is
needed to charge external capacitor connected with VMID pin. If recording and playback start before completion of charge, it
may generate noise. The following is a sequence of recommendation. Refer to the Analog Reference Power Management
Register for the function of VMIDCON.
VMID Power UP/DOWN Sequence (External capacitor 1uF)
Power Up
vmid ( 0V )
Power Down
1/2 Regout Level
Power Down Charge Time
Record or Playback Power Down
VMIDCON
0x0
0x1
0x2
0x0
Min 5ms _{Min 5ms}
Figure 35.
Interrupt circuit
It is possible to check BU26156 operation by IRQ port. IRQ port polarity is changed by thermal protection operation and
speaker short protection operation. IIt is possible to mask Interrupt function and select IRQ interrupt polarity.
In case of BU26156 detects protection operation, BU26156 keeps interrupt status. In case of clear interrupt status, write to
“1” to status register.
IRQB teminal outputs “L” level during RESETB equal “L” level (RESET state). Please mask IRQB signal in this period
RE SETB
IR QB
Min: 1ms
Valid
Figure 36.
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TSZ22111・15・001
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TSZ02201-0V1V0E502570-1-2
Jul.1.2014 Rev.001