The MIC74YQS is a fully programmable serial-to-parallel I/O Expander compatible with the SMBus? (system management bus) protocol. It acts as a "slave" on the bus, providing eight independent I/O lines. Each I/O bit can be individually programmed as an input or output. If programmed as an output; each I/O bit can be programmed as an open-drain or complementary push-pull output. If desired, the four most significant I/O bits can be programmed to implement fan speed control. An internal clock generator and state machine eliminate the overhead generally associated with "bit-banging" fan speed control. Programming the device and reading/writing the I/O bits is accomplished using seven internal registers. All registers can be read by the host. Output bits are capable of directly driving high-current loads such as LEDs.
Provides eight bits of general purpose I/O
Push-pull or open-drain output
Interrupt on input changes
Outputs can directly drive LEDs
Up to 8 devices per bus
5V Tolerant I/O
2-wire SMBus?/I2C? compatible serial interface plus interrupt output
(EN)
