MIC502YM

The MIC502YM is a Thermal and Fan Management IC which supports the features for NLX/ATX power supplies and other control applications. Fan speed is determined by an external temperature sensor, typically a thermistor-resistor divider and optionally a second signal, such as the NLX FanC signal. The MIC502 produces a low-frequency pulse-width modulated output for driving an external motor drive transistor. Low-frequency PWM speed control allows operation of standard brushless dc fans at low duty cycle for reduced acoustic noise and permits the use of a very small power transistor. The PWM time base is determined by an external capacitor. An open-collector over-temperature fault output is asserted if the primary control input is driven above the normal control range. The MIC502 features a low-power sleep mode with user-determined threshold. Sleep mode completely turns OFF the fan and occurs when the system is asleep or OFF.

• Temperature-proportional fan speed control
• Controls any voltage fan
• Over-temperature detection with fault output
• Integrated fan start-up timer
• Automatic user-specified sleep mode
• Supports NTC/PTC thermistors