DC TAIL ROTOR MOTOR, STEERING GEAR MOTOR DRIVE CIRCUIT

DESCRIPTION

UTC UMD9124 is an integrated brush DC motor drive solution

for battery-powered toys, low-voltage or battery-powered motion

control applications. It has H bridge driver and uses the PMOS and

NMOS power transistors with low output resistance. Low

on-resistance ensures the circuit to consume lower power in

operating at a continuous current, and ensures the circuit to

operate stably for a long time. The circuit has a wide working

voltage range from 2.5V to 5V. The maximum continuous output

current reaches 0.5A, and the maximum peak output current can

be 0.8A when VCC is 4V.

UTC UMD9124 has on-chip temperature protection function.

When load motor with low internal resistance is in locked rotor,

UTC UMD9124 output current will increase momentarily, power

dissipation of the circuit will go up sharply, and the chip

temperature will soar. But, when the chip temperature exceeds a

maximum temperature point (typically 160°C) set by internal

temperature protection circuit, the internal circuit will switch off the

on-chip power switching transistor of UTC UMD9124, and switch

off load current, preventing potential safety hazards such as

fuming, igniting of plastic package caused by over temperature etc.

Only after having confirmed that the circuit has returned to safety

temperature, the on-chip temperature hysteresis circuit can be

allowed to re-control the circuit.

FEATURES

* Low standby current (0.1μA typ.)

* PMOS and NMOS power transistors with low output resistance

If IO is 100mA, RON of power transistor is 1.5Ω

If IO is 200mA, RON of power transistor is 1.6Ω

If IO is 300mA, RON of power transistor is 1.7Ω

* Built-in Subsequent stream diode

—No external diode required

* Low input current

Pull-down resistance is 1.8MΩ typical

1.6μA input current when input voltage is 3V

* On-chip thermal shut down (TSD) with hysteresis