EPC Introduces 23 mm GaN Inverter for Robots and Drones

EPC has introduced the EPC91132, a 3-phase BLDC motor drive reference design built around the EPC33110 gallium nitride power module. The circular inverter measures 23 mm in diameter and targets compact motor-drive applications including humanoid robot joints and drone propulsion systems.

The EPC91132 is a GaN-based motor drive inverter used to control small BLDC motors. The design combines power conversion, sensing, control, and motor-position feedback on a single board.

23 mm Diameter Motor Drive

The EPC91132 uses a circular PCB layout with a removable breakout ring. With the outer ring removed, the board measures 23 mm in diameter, allowing it to fit within compact motor assemblies.

EPC notes that the design can be integrated into small drone motors, including systems similar in size to the Vertiq 23-06 platform. The compact footprint is aimed at applications where motor drive electronics must fit within tight mechanical constraints.

EPC33110 GaN Power Module

At the center of the design is the EPC33110, a monolithic GaN power module that integrates three half bridges, gate drivers, bootstrap circuitry, and level shifters within a 6 mm × 6.5 mm QFN package.

The module supports operating voltages from 5 V to 80 V and accepts either 3.3 V or 5 V logic inputs. EPC specifies a typical on-resistance of 11.7 mΩ.

By integrating the gate-drive circuitry within the module, the EPC33110 removes the need for external gate-driver devices and reduces overall component count.

Integrated Control And Sensing

The EPC91132 includes a microcontroller, regulated power supplies, DC bus voltage sensing, current sensing, and embedded overcurrent protection.

A magnetic encoder is included for rotor position and speed measurement, allowing the board to function as a complete motor-control platform. Programming is handled through a dedicated connector, while RS-485 communication provides real-time monitoring capability.

The inverter supports input voltages from 10 V to 60 V.

11 ARMS Continuous Current at 100 kHz

Performance testing showed continuous output current of 11 ARMS per phase when operating from a 48 V supply at PWM switching frequencies up to 100 kHz.

EPC states that the platform was evaluated in both robotic-joint and drone-motor applications. During drone testing, the company reported minimal temperature rise when airflow from the propeller was directed across the inverter.

The combination of high switching frequency, integrated GaN power stages, and compact board dimensions positions the design as a reference platform for small motor-drive applications where size and weight are key considerations.

Learn more and read the original announcement at www.epc-co.com

Technology Overview

The EPC91132 is a 3-phase BLDC motor drive reference design based on the EPC33110 GaN power module. The inverter supports input voltages from 10 V to 60 V, operates at PWM frequencies up to 100 kHz, and delivers 11 ARMS continuous current per phase from a 48 V supply.

Frequently Asked Questions

What motor applications is the EPC91132 designed for?

EPC identifies humanoid robotic joints, robotic wrists and hands, and drone propulsion systems as target applications.

What GaN device is used in the EPC91132?

The inverter is based on the EPC33110 GaN power module, which integrates three half bridges, gate drivers, bootstrap circuitry, and level shifters.

What current can the EPC91132 deliver?

EPC reports continuous output current of 11 ARMS per phase at 48 V and PWM frequencies up to 100 kHz.