VD6283TX datasheet(7/59 Pages) STMICROELECTRONICS

7 / 59 page

3.3.1

Raw and calibration data

The VD6283 features an OTP memory bank to store calibration data. ST performs a light calibration of each

individual channel in production. A calibration factor per channel is then stored in the VD6283 OTP memory. The

user can retrieve both raw data and calibration data through the software driver.

3.3.2

Power up/Power down sequence

Following power up (tPU = 0.03 ms) of the VD6283, some internal registers must be initialized before any mode

(e.g. ALS or Flicker) can operate. To ensure proper initialization of the sensor, one dedicated API function

(STALS_Init) is available in the VD6283 software driver and should be called right after power up.

Before power down of the VD6283, one dedicated API function (STALS_Term) must be called.

Please note the API function STALS_Term should be called only before power down of the actual sensor.

3.3.3

24 bit/16 bit ADC readout

The VD6283 features a 24 bit ADC which converts light information into digital format (i.e. counts). Each channel

count data is proportional to channel irradiance. Note that the minimum reported irradiance level (guaranteed by

design) is 0x000100.

Figure 6. 24 bit ADC readout vs. light level

At low light levels, the ADC data low byte (ALS_CHx_DATA_L) is useful for improving sensing resolution. During

nominal light conditions, the ALS_CHx_DATA_L byte can be discarded and the application can read the sixteen

most significant bits of the ADC (ALS_CHx_DATA_H and ALS_CHx_DATA_M) using the software driver (16 bit

ADC format).

VD6283TX

Operating modes

DS13735 - Rev 1

page 7/59

VD6283TX Datasheet(PDF) 7 Page - STMicroelectronics