Germany-based Manufacturer Seeks to Innovate Low-power IoT with New Driver ICJanuary 13, 2020 by Gary Elinoff
The TMC7300 can deliver two amps to drive either one or two DC motors, relays, and LEDs.
Germany-based company Trinamic has introduced TMC7300, a low-voltage driver designed for battery-operated equipment, such as battery-operated motors, IoT, handheld devices, POS applications, mobile medical devices, toys, and cameras.
The standby current of the device is 50nA or less, and the unit requires two AA batteries or one or two LiB cells to operate. Because space is just as much at a premium as is power in such applications, the unit is offered in a 3mm x 3mm 20-pin QFN package.
The TMC7300. Image used courtesy of Trinamic
The TMC7300 is the second IC that Trinamic has designed with motor control in mind. The previously announced TMC2300 is also aimed at similar low-power applications. The TMC2300 is designed specifically for two-phase stepper motors. It operates over a 1.8V to 11V range, similar to the newer TMC7300.
Block diagram of the TMC7300. Image used courtesy of Trinamic
The TMC7300 features two full-bridges for control of the direction, velocity, and torque of two DC motors using simple UART control. Even with a low supply voltage, the unit’s internal charge pump allows for a typical RDSON of 170 milliohms.
Modes of Operation
The TMC7300 was designed principally with motor control in mind, and it can drive motor control in a variety of ways. However, the versatile driver IC can also be used to drive other inductive loads as well as LEDs.
As described by Michael Randt, founder and CEO of the company, “By rolling out our new family of driver ICs for battery-powered applications, we want to fuel the imagination of engineers around the world by giving them the tools needed to develop new applications and turn proven concepts into easy-to-use portable devices for both consumers and professionals.”
DC Motor Operation
In DC motor operation mode, the CPU can control either one or two motors using its UART interface. The motor is directly controlled by the duty cycle of the TMC7300’s internal PWM generator. There is also a negated duty cycle that can cause the motor to turn in the opposite direction.
UART interface to control 1 DC motor. Image used courtesy of Trinamic
Note that the two outputs can be paralleled to deliver twice the power to only one motor as depicted below.
UART interface for control of 2 DC motors. Image used courtesy of Trinamic
Half-bridge Peripheral Driver
In half-bridge peripheral driver mode, one of the two full bridges can be used to drive a DC motor. In the example below, the other half-bridge drives a solenoid and an LED.
Half-bridge peripheral drivers. Image used courtesy of Trinamic
It is also possible to split the full-bridge that drives the motor in the above image into the second pair of half-bridges. In this manner, there are four half-bridges that drive four separate loads.
Half-bridge driver mode. Image used courtesy of Trinamic
Evaluation and Support Tools
The TMC7300-Eval-Kit allows the user to more quickly grasp the usage of the TMC7300. All the signals transmitted between the controlling MCU and the chip itself are easily available.
The TMC7300-EVAL. Image used courtesy of Trinamic
There is also an extensive library of sample codes readily accessible to the user.