Trinamic Debuts 3-phase MOSFET Gate Driver for PMSM and BLDC motors

The TMC6140-LA offers a complete solution for motor drive applications, offering a 30% improvement in power efficiency. The unit is offered by Trinamic, now part of Maxim. Its high level of integration allows for a simplified design process and allows engineers to offer complete solutions with a smaller BOM counts.

The TMC6149-LA. Image courtesy of Maxim

The TMC6140-LA 3-phase MOSFET gate driver includes all three bottom shunt amplifiers internally. This enables complete motor drive solutions with efficiency improved by 30% over similar solutions. These integrated shunt amplifiers provide current sensing and enable better commutation of the electric motor being controlled, as well as stronger diagnostics

As per Michael Randt, founder of Trinamic Motion Control, “The integrated current sense and diagnostics features are key for enabling functional safety without adding complicated circuitry or additional components to any system’s design.” He goes on to say that, “This allows engineers to increase efficiency by 30 percent with minimal effort.”

 

A Single External Power Supply Rail

All required supply voltages are generated internally. The unit generates a fixed 3.3V rail voltage through a buck converter, supplying up to 0.5 A, generating sufficient power for I/O and for an external microcontroller. An internal Schottky diode is operational up to a 100mA load, and if more current is needed, an external diode has to be mounted in parallel.

 

Applying the TMC6140

The six MOSFETs depicted below are chosen as per the voltage and current required by the PMSM or BLDC motor being controlled and powered. The three current sense resistors (not shown) are chosen as a function of the motor’s maximum coil current.

Simplified block diagram for the TMC6149-LA. Image courtesy of Datasheet

The device also offers a DIAG output that communicates with the external microcontroller via UART-TxD for further diagnostics. There are two low power modes consuming a maximum of 0.25 mA in standby. The gate driver also offers two different power down modes.

 

Electrical Parameters

Maximum operational supply voltage is 30V

RDS(ON), typical values, low side and high side, are 1.8Ω and 1.2Ω, respectively

Total supply current (typ), with no active driver:

• When not in low power mode: 4mA
• Low power mode 1: 1mA
• Low power mode 0: 0.2mA

 

Applications

TMC6140 is well suited for applications in the range of 5 V to 24 V with motor power requirements ranging from 1W Watt to 1kW.

The wide range of potential deployments include:

• Industrial Drives
• Power Tools
• Robotics
• Textile Machines
• Factory Automation
• Laboratory Automation
• Pumps
• Fans
• Battery Operated Devices

 

Physical

The gate driver is available in a 36 pin, 5 x 6mm QFN package

The device operated over a junction temperature range of -55 to 125°C

 

Getting to Market Faster

The TMC6140-EVAL allows designers to evaluate the TMC6140. It works with Trinamic's free TMCL-IDE graphical user interface. Designers will be able to monitors real-time behavior with graphs, and logs provided. Data is stored, and the settings are exportable for firmware development.