DESCRIPTION

· The MAX7347/MAX7348/MAX7349 are I2C interfaced peripherals for managing up to 64 key switches, with static monitoring to ensure low-EMI operation.

· The MAX7347 monitors up to 24 switches, the MAX7348 up to 40, and the MAX7349 up to 64, supporting metallic or resistive switches up to 1k Ω.

· Features include key debouncing, FIFO event queue, and an interrupt output for key press alerts.

· The MAX7348/MAX7349 include a tone generator for key-click sounds or alarm tones, with frequencies covering the 5th musical octave and beyond.

· Available in various packages, these devices operate from -40°C to +125°C.

FEATURES

· 400kbps, 5.5V-tolerant 2-wire serial interface.

· Operates from 2.4V to 3.6V.

· Monitors up to 64 keys (MAX7349), 40 keys (MAX7348), or 24 keys (MAX7347).

· FIFO queues up to 8 debounced key events.

· Configurable key debounce time, autorepeat rate, and delay.

· Low-EMI design with static matrix monitoring.

· Hardware interrupt on debounced events, FIFO level, or after a definable time period.

· Up to six open-drain logic outputs capable of driving LEDs.

· Sounder output for automatic key clicks with 14 programmable musical frequencies.

· Continuous or programmable sounder duration.

· Easy automatic single-tone and dual-tone alarm sound generation.

· Four I2C address choices and selectable 2-wire serial bus timeout.

· Shutdown current under 10 µA.

APPLICATIONS

· Medical Instruments.

· Instrumentation Panels.

· Security and Access systems.

· Industrial Controls.