The MAX7370 I²C-interfaced peripheral provides microprocessors with management of up to 64 key switches, with optional GPIO and PWM-controlled LED drivers.

The key-switch drivers interface with metallic or resistive switches with on-resistances up to 5kΩ. Key inputs are monitored statically, not dynamically, to ensure low-EMI operation. The IC features autosleep and autowake modes to further minimize the power consumption of the device. The autosleep feature puts the device in a low-power state (1µA typ) after a timeout period. The autowake feature configures the device to return to normal operating mode from sleep upon a keypress.

The key controller debounces and maintains a FIFO buffer of keypress and release events (including autorepeat, if enabled). An interrupt (active-low INT) output can be configured to alert keypresses, as they occur, or at the maximum rate.

The same index rows and columns in the device can be used as a direct logic-level translator.

If the device is not used for key-switch control, all keyboard pins can be used as GPIOs. Each GPIO can be programmed to one of the two externally applied logic voltage levels. Four column ports (COL7–COL4) can also be configured as LED drivers that feature constant-current and PWM intensity control. The maximum constant-current level for each open-drain LED port is 20mA. The intensity of the LED on each open-drain port can be individually adjusted through a 256-step PWM control.

The device is offered in a 24-pin (3.5mm × 3.5mm) TQFN package with an exposed pad, and small 25-bump (2.159mm x 2.159mm) wafer-level package (WLP) for cell phones, pocket PCs, and other portable consumer electronic applications.

The device operates over the -40°C to +85°C extended temperature range.