By enabling the speed of fans, blowers and extractors to be simultaneously controlled by both pwm and thermistor input signals, the AM4964 motor driver from Diodes, Incorporated helps create more responsive cooling systems for PCs, servers and industrial instrumentation. A single-phase, full-wave, brushless dc motor driver, the AM4964 operates from a 12V supply and delivers a peak motor current of up to 1A. Motor speed is varied between low and high temperature set-points in response to ambient temperature and pwm input signal.
Set-points and maximum pwm output are easily adjusted using just three external resistors. The device offers a tachometer output, a bias output for a differential unbuffered Hall sensor and dedicated inputs for 3- or 4-pin Hall sensors for rotor position detection. A highly-integrated device in the TSSOP-20EP package, the AM4964 also includes a built-in oscillator, removing the need for an external capacitor; a minimum speed-setting circuit; and adjustable alpha slope technology to support different speed curve requirements.
To protect the motor coil, the driver incorporates thermal shutdown, rotor lock detection and auto-restart functions. The AM4964 single-phase, full-wave motor driver is priced at $0.38USD each in 10K piece quantities.