TSL2672

DIGITAL PROXIMITY DETECTOR

TAOS133 − MAY 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

proximity values outside a user-defined range. While the interrupt function is always enabled and its status is

available in the Status register (0x13), the output of the interrupt state can be enabled using the proximity

interrupt enable (PIEN) field in the Enable register (0x00).

Two 16-bit interrupt threshold registers allow the user to set limits below and above a desired proximity range.

An interrupt can be generated when the proximity data (PDATA) is less than the proximity interrupt low threshold

(PILTx) or is greater than the proximity interrupt high threshold (PIHTx).

It is important to note that the thresholds are evaluated in sequence, first the low threshold, then the high

threshold. As a result, if the low threshold is set above the high threshold, the high threshold is ignored and only

the low threshold is evaluated.

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

persistence filter allows the user to specify the number of consecutive out-of-range proximity occurrences

before an interrupt is generated. The persistence filter register (0x0C) allows the user to set the proximity

persistence filter (PPERS) values. See the persistence filter register for details on the persistence filter values.

Once the persistence filter generates an interrupt, it will continue until a special function interrupt clear command

is received (see Command register).

Prox

ADC

Prox

Data

Prox

Integration

Channel 0

Upper Limit

Lower Limit

Prox Persistence

PILTH(r 0x09), PILTL(r 0x08)

PIHTH(r 0x0B), PIHTL(r 0x0A)

PPERS(r 0x0C, b7:4)

Channel 1

Figure 12. Programmable Interrupt