ALC5642-VF
Datasheet
7.2. Power Supply On/Off Sequence
To prevent pop noise and make sure function work normally, following power on and off sequence are
recommended.
Case1: For SPKVDD is from battery:
Power On Sequence: (Sequentially turn on power pins)
1. Pull LDO1_EN pin (Pin#44) to DGND (digital ground)
2. SPKVDD power supply on
3. DCVDD power supply on (This step is required if DCVDD is supplied by external 1.2V power. This
step and Step 5 are exclusive.)
4. DBVDD/AVDD/DACREF/CPVDD=1.8V power supply on
5. DBVDD power supply on (This step is required if DBVDD is supplied higher than 1.8V)
6. MICVDD power supply on (This step is required if MICVDD is supplied by external power)
7. Pull LDO1_EN pin (Pin#44) to DBVDD (This step is required if DCVDD is generated by internal
LDO. This step and step 3 are exclusive. If DCVDD is supplied by external 1.2V, LDO1_EN must be
pulled low.)
8. Initialize voice DSP and codec of ALC5642.
9. Power down voice DSP of ALC5642. (Write 0x0400’h to register MX-C6’h)
Power Off Sequence: (Sequentially turn off power pins)
1. Power down voice DSP of ALC5642. (Write 0x0400’h to register MX-C6’h)
2. Power down all Codec function (Write 0x0000’h to register MX-00’h)
3. Pull LDO1_EN pin (Pin#44) to DGND (If internal LDO is used to generate DCVDD)
4. MICVDD power supply off (If MICVDD is supplied by external power)
5. DBVDD power supply off (This step is required if DBVDD is supplied higher than 1.8V)
6. DBVDD/AVDD/DACREF/CPVDD power supply off
7. DCVDD power supply off (If DCVDD is supplied by external power)
8. SPKVDD power supply off
Multi-Channel Audio Hub/CODEC with embedded Voice
DSP and SounzRealTM Digital Sound Effect
12
Rev. 0.93
REALTEK [ Realtek Semiconductor Corp. ]
