PRELIMINARY
SF104-P01
SF3013M Fingerprint Image Sensor Module User Manual
Page - 9
Two cascaded programmable gain amplifier are used for conditioning the sensor signal
before converted by ADC. Register REG1/REG_PGA bit [1:0] is for the control of PGA1 gain,
and register REG1/REG_PGA bit [7:4] for the control of PGA2 gain.
The ADC bias current and input voltage range is controlled by BIAS, (VRT-VRB) and
VRB parameters in REG3/REG_ADC. See section 5.0 for the detail of the registers.
3.3 Command and registers
The SF104 operation is controlled by sending commands and setting control registers
through the SPI interface. The SF104 SPI interface follows the SPI protocol with CPHA=0
and CPOL=0 as SPI mode 0.
There are 6 command codes to program the chip:
160x160
Pixel
array
Sample
&hold
ADC
MCU
Gain
Gain
VRT
VCM
VRB
PGA1 PGA2
