SNAD01B datasheet(11/31 Pages) SONIX

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SNAD01B

8-CHANNEL 8-BIT ADC

3. After SNAD01B enters power down (mode 1: command 111), SNAD01B sends “1” out to

DIO until a valid logic transition appears on any wakeup-enabled digital input channel. Once

the transition occurs, SNAD01B toggles DIO to “0” to inform host controller. After receiving

“0” from DIO, host controller should turn START back to “1” to inform SNAD01B that the

power-down stage is over. Otherwise, SNAD01B keeps sending out “1” to DIO and does not

recognize any other transitions any the channels.

4. The CLK may stop but START ought to remain at LOW level in the whole power down

mode.

Note:

1. Wakeup function is only dedicated to the channel which is digital input type AND

wakeup-enabled.

2. In SNAD01B version, the standby current will more than 50uA in AD conversion

reference voltage use “REF” pin connected external voltage.

Bandgap reference

Figure8 Circuit diagram of ADC bandgap reference selection

VDD

VSS

REF

PAD

to reference

high of the ADC

RF+RF MB

1.2v

bandgap

reference

ON CHIP

OFF CHIP

If the internal bandgap reference is turned ON (RF=1), the reference voltage of ADC is

supplied by output voltage of the internal bandgap reference circuit. This bandgap

consumes about 300

µA. The output voltage of bandgap reference is around 1.17V

typically.

Note: MB for chip test only. Always set MB=0 with command (011) in System Power-On

Initialization Routine.

Version: 1.3

July 31, 2003

SNAD01B Datasheet(PDF) 11 Page - SONiX Technology Company