MAX13037

The MAX13037/MAX13038 contact monitor and level shifters monitor and debounce eight remote mechanical switches and assert an interrupt (active-low 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 ground-connected 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.

The MAX13037/MAX13038 feature a low dropout (LDO) linear regulator capable of supplying up to 150mA of current. The MAX13037 LDO has an output voltage of +5V, whereas the MAX13038 has an output voltage of +3.3V. The MAX13037/MAX13038 also feature a watchdog timer and an open-drain reset output with adjustable timing.

The MAX13037/MAX13038 operate with a +6V to +26V battery voltage applied to BAT. The MAX13037/MAX13038 are available in a 6mm x 6mm, 36-pin TQFN package and operate over the automotive -40°C to +125°C temperature range.

Applications

• Body Computers
• Electric Sunroofs
• Other Control ECUs
• Seat Movers
• Window Lifters