ZHCSMR2B December 2020 – December 2021 BQ76942
The ALERT pin is a multifunction pin that can be configured either as ALERT (to provide an interrupt to a host processor), a thermistor input, a general purpose ADC input, a general purpose digital output, or an HDQ serial communication interface. The pin can be configured as active-high, active-low, or open-drain to accommodate different system design preferences. When configured as the HDQ interface pin, the pin will operate in open-drain mode.
When the pin is configured to drive an active high output, the output voltage is driven from either the REG18 1.8-V LDO or the REG1 LDO (which can be programmed from 1.8 V to 5.0 V).
The BQ76942 device includes functionality to generate an alarm signal at the ALERT pin, which can be used as an interrupt to a host processor. When used for the alarm function, the pin can be programmed to drive the signal as an active-low or hi-Z signal, an active-high or low signal, or an active-low or high signal (that is, inverted polarity). The alarm function within the BQ76942 device includes a programmable mask to allow the customer to decide which of many flags or events can trigger an alarm.