AH5795 (NRND)

Description

The AH5795 is a single chip solution for driving single-coil brushless direct current (BLDC) fans and motors. The integrated full-bridge driver output stage uses soft switching to minimize audible switching noise and electromagnetic interference (EMI) providing a low noise solution. Motor speed can be control°C by either changing the duty ratio of the PWM signal at the PWM pin or by varying the supply voltage at Vdd pin. To help protect the motor coil, the AH5795 provides Rotor Lock Protection which shuts down the output drive if rotor lock is detected. The device automatically re-starts when the rotor lock is removed. Over temperature shutdown provides thermal protection for the device. A Tachometer output is provided by open-drain Frequency Generator (FG) Pin which allows external interface to monitor motor rotation or speed. The FG output is the magnetic change frequency.

Feature(s)

Supports single-coil full-wave BLDC fan drivers

Built-in Hall sensor and input amplifier

Operating voltage: 1.8V to 6V

Speed control methods - Vdd voltage speed control (PWM pin tied to Vdd) - PWM signal speed control via PWM pin

Soft switching for low noise DC fan motor applications

Rotor Lock Protection (Lock detection, output shutdown and automatic re-start)

Toff clear when PWM is low for greater than 65ms

Thermal protection

Tachometer (FG) output

No external timing capacitor - Reduces the numbers of external components required

Low profile package: TSOT23-6 and DFN2020C-6

“Green” Molding Compound (No Br, Sb)

Application(s)

3.3V / 5V BLDC Cooling Fans

Netbook/ Notebook BLDC fans

Instruments cooling fans

Low Voltage/ Low Power BLDC Motors