Drivers for BDC motors incorporate on-chip current sensing

Texas Instruments introduced a family of three brushed DC gate drivers featuring the industry’s first device with integrated current sensing. With this integration, designers using the DRV8871 can avoid the power loss, heat generation and cost associated with using external sense resistors. Compared to competitive devices, the DRV8871 motor driver family helps reduce design complexity, power consumption and board space in end equipment such as multifunction printers, appliances and industrial machines.

Expanding TI’s brushed DC motor driver portfolio, the DRV8871 is one of three new brushed DC drivers with integrated field-effect transistors (FETs), developed for space-constrained designs. The DRV8870 features integrated regulation to limit current to an external current-sense resistor. The DRV8872 provides fault monitoring to increase system reliability.

Key features and benefits

• Reduced system complexity: When designing with the DRV8871, the elimination of discrete sense resistors reduces board space by up to 25 percent.
• Optimal power consumption: The devices use standard low-cost, low-power resistors to set the current threshold, limiting startup and stall inrush currents. The ability to limit current to a known level can significantly reduce the system power requirements and bulk capacitance needed to maintain a stable voltage, especially for motor startup and stall conditions.
• Simplified design: Board layout with accurate current regulation is simplified because no sense routing is required with the DRV8871.
• Wide supply range: The devices offer a wide 6.5- to 45-V motor-supply voltage to support industry-standard 12- and 24-V supplies.

Tools and support
The DRV8870EVM, DRV8871EVM and DRV8872EVM evaluation modules (EVMs) demonstrate the capabilities and performance of their respective brushed DC motor drivers. The EVMs also incorporate the TPS7A16 low-dropout regulator (LDO) and the TLC555 low-power timer. They are available for purchase for US$49 via the TI store and authorized distributors.

To support their brushed DC motor challenges, designers can search for solutions, ask questions, and share knowledge with fellow engineers and TI experts on the TI E2E™ Community Motor Driver forum.

Pricing and availability
The 8-pin DRV8871 family is available now in a 4.9-mm-by-6.0-mm thermally enhanced small outline package (HSOP). Pricing in 1,000-unit quantities starts at US$1.40 for the DRV8871 and US$1.28 for the DRV8870 and DRV8872.

The DRV8871 family is the latest addition to TI’s portfolio of motor drivers. From drop-in and spin to highly complex industrial motors, TI has the industry’s most scalable motor solutions across a broad range of voltage, current, interface, integration and control options.

Texas Instruments
www.ti.com