This is the instruction manual for the Micrel MIC74 evaluation board, which introduces the function and characteristics of the evaluation board.
This manual describes the MIC74 Evaluation Board, an SMBus™ VO expander and fan controller evaluation platform. It includes a general description, a packing list, and step‑by‑step procedures for configuring inputs, outputs, and fan mode.
The document explains three power‑supply options, jumper settings for slave address selection, pull‑up resistor requirements, and how to enable fan control. Appendices list SMBus resources and part numbers for connectors and regulators.
| Supported dual power supplies | 5 V and 2.7‑3.6 V |
|---|---|
| MIC5205 regulator output voltage | 3.3 V |
| MIC29152 regulator maximum input voltage | 26 V |
| Fan supply voltage | 12 V |
| Required primary power supply | 5 V, 100 mA regulated |
The board needs a 5 V, 100 mA regulated supply and, for fan control, a 12 V supply capable of the fan’s current.
Write 0x02 to the DEV_CFG register to set the fan bit, then write the desired value to FAN_SPEED.