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 from Diodes Incorporated is priced at $0.38USD each in 10K piece quantities.