GENERAL DESCRIPTION
The MAX13037/MAX13038 automotive contact monitor and level shifters monitor and debounce eight remote mechanical switches and assert an interrupt (INT) if a switch changes state. The state of each switch is sampled through an SPI™ interface by reading the status register. Any switch can be prohibited from asserting an interrupt by writing to the command register. Four of the switch inputs are intended for ground-connected switches (IN0–IN3) and the other four inputs (IN4–IN7) are programmable in groups of two for either groundconnected or battery-connected switches. Two switch inputs (IN0, IN1) have direct level-shifted outputs (DO0, DO1) to be used for PWM or other timing-based signals. Switch input thresholds are set to 50% of the voltage applied to BATREF. The threshold hysteresis is set by connecting an external resistor from HYST to ground. The MAX13037/MAX13038 supply an adjustable wetting current to each closed switch to clean mechanical switch contacts that are exposed to adverse conditions.
Maxim Integrated
