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Automotive ICs monitor eight remote switches

Sunnyvale, Calif. — Maxim Integrated Products has introduced the MAX13037 and MAX13038 automotive contact monitors and level shifters with an integrated voltage regulator, watchdog timer, and reset functions. These devices monitor and debounce eight remote mechanical switches while consuming only 28 microamp (typical) supply current.

To achieve this low current consumption, the MAX13037/MAX13038 devices make innovative use of programmable polling periods and a programmable scanning period, said Maxim. Providing a wide input-voltage range (+/-45 V), high ESD protection (+/-8 kV on switch inputs), adjustable wetting current, and an LDO, the MAX13037/MAX13038 devices are suitable for harsh automotive environments such as body controller applications.

The MAX13037/MAX13038 devices operate from a 6-V to 26-V battery voltage and withstand a 42-V load-dump. A separate 2.7-V to 5.5-V logic-supply input sets the interface voltage. The MAX13037 features a 5-V LDO regulator, and the MAX13038 features a 3.3-V LDO regulator. Both LDOs are capable of providing up to 150 mA.

To minimize the ECU's overall current consumption, the MAX13037/MAX13038 feature an open-drain interrupt output that is active in the absence of a logic supply and can be used to wake up an external microcontroller from a sleep state. In addition, any of the switch inputs can be prohibited from asserting an interrupt by writing to the appropriate register through the SPI-compatible interface. The SPI interface eases programming, and is used to read the switch status and configure the operating characteristics of each device.

The high modularity of the MAX13037/MAX13038 minimizes external component count and allows multiple devices to be cascaded to monitor/configure additional switches. The devices provide a complete solution for mechanical switch interfacing. All eight switch inputs feature programmable wetting current and switching hysteresis. Four inputs are for ground-connected switches, and the other four inputs can be programmed in groups of two as battery- or ground-connected switches. In addition, the microcontroller interface pins can be configured to have direct level-shifting outputs for interfacing with PWM, low-voltage, or other timing signals.

The MAX13037/MAX13038 are available in a lead-free, RoHS-compliant, 6 x 6-mm, 36-pin TQFN package, and are fully specified over the -40° to +125°C automotive temperature range.

Pricing: Starts at $2.16 (1000-up, FOB USA).
Datasheet: MAX13037

Maxim Integrated Products , 1-888-629-4642, www.maxim-ic.com

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