MIC502 Datasheet | Micrel Semiconductor

Micrel Fan Management IC Advance Information General Description The MIC502 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 “Fan C” 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 overtemperature 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 a userdetermined threshold. Sleep mode pletely turns off the fan and occurs when the system is asleep or off (both control inputs very low). A plete shutdown or reset can also be initiated by external circuitry as desired. The MIC502 is available as 8-pin plastic DIP and SOIC packages in the - 40°C to +85°C industrial temperature range. Features - - - - - - - - - - - - - - - - - Temperature-proportional fan speed control Low-cost, efficient PWM fan drive 4.5V to 13.2V IC supply range Controls any voltage fan Overtemperature detection with fault output Integrated fan startup timer Automatic user-specified sleep mode Supports low-cost NTC/PTC thermistors 8-pin DIP and SOIC packages NLX and ATX power supplies Personal puters File servers Tele and networking hardware Printers, copiers, and office equipment Instrumentation Uninterruptable power supplies Power amplifiers Applications Ordering Information Part Number MIC502BN MIC502BM Temperature Range - 40°C to +85°C - 40°C to +85°C Package 8-pin Plastic DIP 8-pin SOIC Typical Application 12V T1 R3 R4 R2 R1 1 2 3...