STMicro Brings SPI Control to Three-Phase Brushless Motor Gate Drivers

STMicroelectronics has expanded its STDRIVE102 gate-driver family with two new additions—the STDRIVE102P and STDRIVE102BP—both of which feature an SPI interface for configuring gate current and operational parameters. Designed to drive six external N-channel power MOSFETs in a three-phase inverter topology, the devices operate across a supply voltage range of 6V to 50V, making them well-suited for battery-powered equipment including power tools and domestic appliances.

Each driver can be programmed to source up to 1A and sink up to 2A, with slew-rate regulation available without external resistors. That last detail is a practical convenience; eliminating gate resistors from the BOM simplifies PCB layout and reduces component count without sacrificing switching control. An ultra-low standby current of 50 nA (typical) rounds out the power-management picture, a figure that matters considerably in always-connected or intermittently active portable designs.

Integrated Power Management and Protection Features

An advanced charge pump integrated into all STDRIVE102 devices keeps the high-side driver circuitry operational continuously, enabling PWM duty cycles up to 100% without additional bootstrapping complexity. On-chip 12V and 3.3V LDOs supply the internal low-side drivers and embedded analog front-end and can also extend power to external components, a feature that can meaningfully trim bill-of-materials costs in space-constrained designs.

The STDRIVE102BP carries the more capable analog front-end of the two: three programmable-gain amplifiers (PGAs) and three comparators for multi-shunt motor current measurement. Each PGA and comparator can be enabled or disabled independently, or the entire AFE can be shut down to conserve energy. The STDRIVE102P offers a leaner arrangement, one PGA and one comparator, suited to simpler single-shunt topologies.

With a wide voltage range and ultra-low standby current, the STDRIVE102 family is an ideal component of a wide variety of power tools. Image used courtesy of Adobe Stock

Both devices include undervoltage lockout, thermal shutdown, and drain-source voltage monitoring on both the high and low sides. That dual-sided VDS monitoring provides redundant overcurrent protection, a meaningful safety margin in motor-drive systems where fault events can escalate quickly. The STDRIVE102BP adds a dedicated fault-indicator pin for the main supply voltage, offering an additional diagnostic signal for system-level fault handling.

Evaluation Hardware and Availability

STMicroelectronics offers evaluation boards, the EVLDRIVE102P and EVLDRIVE102BP, built around ST’s STL220N6F7 power MOSFETs in a three-phase inverter configuration. Both boards are compatible with the Nucleo family of STM32 development boards and integrate with the X-CUBE-MCSDK motor-control software package, which should lower the barrier to prototyping considerably for teams already working within ST’s ecosystem.

The STDRIVE102P is available now in a 5 mm x 5 mm 40-pin VFQFPN package from $1.23, with the STDRIVE102BP in a 6 mm x 6 mm 48-pin VFQFPN from $1.29, both at 1,000-unit quantities. For engineers working on cordless appliances, e-bikes, robotic platforms, or any battery-fed motor application where standby efficiency and compact integration matter, the STDRIVE102 series looks like a genuinely competitive option, and at those price points, it’s easy to justify spinning an evaluation board to see how it performs.