The 33993 is designed to independently monitor the OPEN/CLOSE status of up to 22 switches. Eight programmable sense inputs verify a connection to ground or VBAT while 14 additional programmable inputs verify a connection to ground only.
A 22:1 analog multiplexer is incorporated to read input analog voltages. The 33993 interfaces to a microcontroller via 3.3/5.0 V SPI protocol. Whenever a switch changes state, the microcontroller is automatically alerted.
A Sleep mode provides a low quiescent current for critical power conservative applications. The Normal mode accommodates programming; e.g., pull-up or pull-down contact detection currents, contact wetting current, wetting current time, Interrupt time, AMUX.