TMD2771

DIGITAL ALS

and PROXIMITY MODULE

TAOS143B − SEPTEMBER 2012

12

r

r

Copyright

E 2012, TAOS Inc.

The LUMENOLOGY

r Company

www.taosinc.com

Interrupts

The interrupt feature simplifies and improves system efficiency by eliminating the need to poll the sensor for

a light intensity or proximity value. The interrupt mode is determined by the PIEN or AIEN field in the ENABLE

register.

Four 16-bit-wide interrupt threshold registers allow the user to define thresholds above and below a desired light

level. For ALS, an interrupt can be generated when the ALS C0DATA exceeds the upper threshold value (AIHTx)

or falls below the lower threshold (AILTx). For proximity, an interrupt can be generated when the proximity data

(PDATA) exceeds the upper threshold value (PIHTx) or falls below the lower threshold (PILTx).

To further control when an interrupt occurs, the device provides an interrupt persistence feature. This feature

allows the user to specify a number of conversion cycles for which an event exceeding the ALS interrupt

threshold must persist (APERS) or the proximity interrupt threshold must persist (PPERS) before actually

generating an interrupt. Refer to the register descriptions for details on the length of the persistence.

CH1

ADC

CH1

Data

Prox

ADC

Prox

Data

CH0

ADC

CH0

Data

Prox

Integration

Upper Limit

Upper Limit

Lower Limit

Lower Limit

Prox Persistence

PILTH(r 09), PILTL(r 08)

AIHTH(r 07), AIHTL(r 06)

ALS Persistence

AILTH(r 05), AILTL(r 04)

PIHTH(r 0x0B), PIHTL(r 0x0A8)

PPERS(r 0x0C, b7:4)

APERS(r 0x0C, b3:0)

Channel 1

IR Only

Channel 0

Visible and IR

Figure 10. Programmable Interrupt