Diodes ZXBM1021 motor pre-driver

The ZXBM1021 is a single-phase, brushless, DC motor pre-driver. It provides a variable speed control solution for cooling fans, blowers, extractors, motors and pumps in a variety of consumer and industrial products.

By integrating an array of normally external components, including a PWM integrator and MOSFET buffers, the flexible pre-driver enables designers to greatly simplify system architecture and reduce overall board component count.

The pre-driver can closely control motor speed via the direct application of either an external PWM signal, DC voltage signal or thermistor network input. Through the integration of Hall bias and amplifier circuits, compatibility with all types of Hall effect sensor is assured.

An open-collector frequency generator pin provides a tachometer output enabling external monitoring of rotation and speed. To prevent motor stalling or speed falling below a minimum value in the event of loss of control signals, the product allows the setting of a minimum speed.

Offering high-side and low-side drive outputs, with 50 mA sink and 100 mA source/sink capability, the device can be accurately matched to the needs of external H-bridge switches and motor powers without the need for additional buffering. A separate low-side output drive supply voltage pin also provides the ability to adjust external low-side MOSFET turn-on speed independently of turn-off speed to help minimise EMI noise and shoot-through.

An operating voltage range of 6.8 to 18 V means the pre-driver will support 12 V motors directly, and 24 V and 48 V motors via an external voltage regulator. With a programmable overcurrent limit, the pre-driver is able to detect locked rotor conditions and protect the H-bridge and motor windings from overheating or burnout, instigating a soft start on removal of the rotor lock to minimise motor inrush current.

Supplied in the small footprint, low-profile and thermally enhanced U-QFN4040-20 chip package and with a wide operating temperature range of -40 to +110°C, the product is suited for space-constrained and thermally demanding applications.