SFH 7779

DATASHEET

DATASHEET

31 | Version 1.7 | 2023-05-24

INT modes

The Interrupt function compares ALS and PS measurement values with the current interrupt threshold level. PS and ALS

VIS Interrupt status is readable via register 0x4Ah or at the INT pin of the sensor.

The Interrupt persistence function is only valid for PS measurements and is defined in register (0x43h). The INT pin of the

SFH 7779 is open drain output and should be pulled up to VI/O by an external resistor. When VDD is supplied the INT pin

is high impedance (inactive). The INT status becomes inactive by writing INT reset command, reading the INT status

register or performing a software reset. The INT status stays in its last state when the sensor is set to the standby mode.

In the INT active state “low” the sensor consumes ~25µA extra current. Therefore OSRAM recommends to set the INT

state to high impedance before setting the sensor in standby mode.

Following ALS and PS INT modes are described for the unlatched mode. In latched mode the switching back to the

“inactive” INT state is depending on a interrupt reset or the read of the INT status register.

ALS INT mode:

The ALS VIS threshold levels high (register 0x4Fh & 0x50h) and low (register 0x4Fh & 0x50h) are only valid for the

ALS VIS measurement values. The ALS VIS INT mode is fixed and can not be adapted via register. The thresholds

define a window with following functionality:

ALS INT is active, if the ALS VIS measurement values are outside the window.

ALS INT is inactive, if the ALS VIS measurement results are inside the window.

PS INT Modes: Bit <5;4> of INTERRUPT_CONTROL register (0x4Ah)

00 PS_TH is only active:

The INT state is active it the PS measurement result is equal or higher than the set PS_TH high threshold.

The INT state is inactive, if the PS measurement result is lower than the set PS_TH high threshold.

01 PS_TH & PS_TL (PS high & low threshold) are active as hysteresis:

PS_TH and PS_TL are working as a hysteresis. If the PS measurement signal is higher than the PS high threshold

(PS_TH) the INT state is switched to active. If the PS measurement signal is lower than the PS low threshold

(PS_TL) the INT state is inactive. If once interrupt signal becomes active, INT status is kept active until

measurement result becomes less than PS_TL register value.

10 PS_TH & PS_TL (PS high & low threshold) are active as outside detection:

In case of “PS outside detection” mode interrupt signal inactive means that measurement result is within registered

threshold level and interrupt signal active means measurement result is out of registered threshold level.