Texas Instruments DRV8812RHDT

Overview

DRV8812RHDT from Texas Instruments is a dual H-bridge stepper motor controller IC designed for bipolar stepper or dual DC motor drive in automated equipment. It operates from 8.2 V to 45 V, delivers up to 1.6 A per bridge at 24 V/25°C, supports four-level winding current control (100%/71%/38%/0%), and integrates overcurrent, thermal shutdown, UVLO, and fault reporting via open-drain nFAULT - used in printers, video security cameras, and factory automation.

For engineers reviewing the DRV8812RHDT datasheet, DRV8812RHDT pinout, DRV8812RHDT application, or DRV8812RHDT equivalent, key selection considerations include its 28-pin VQFN PowerPAD™ package, programmable decay mode (fast/slow/mixed), parallel PHASE/ENBL interface, integrated 3.3-V reference output, and dual independent current regulation with external sense resistors.

Technical Context

The DRV8812RHDT implements two independent NMOS H-bridge drivers with fixed-frequency PWM current chopping, where each bridge uses a 5× gain current sense amplifier comparing I_SENSE × 5 against an externally applied reference voltage (AVREF/BVREF). Current magnitude is digitally scaled per bridge using AI0/AI1 and BI0/BI1 inputs to select 100%, 71%, 38%, or 0% of full-scale.

Decay behavior is unified across both bridges and selected by the DECAY pin: logic low = slow decay (LS-FET recirculation), open = mixed decay (75% fast + 25% slow), logic high = fast decay (H-bridge reversal). Internal protection includes analog overcurrent detection independent of sense resistor value, thermal shutdown at 150–180°C, and VM undervoltage lockout at 7.8–8.2 V.

Key Specifications

Pinout & Package

The DRV8812RHDT is housed in a 28-pin VQFN package (5.00 mm × 5.00 mm) with exposed PowerPAD™ thermal pad (RHD suffix), optimized for high-power density and PCB heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual H-bridge motor controller applications.

Compared with TB6600HG and DRV8825, the DRV8812RHDT uniquely balances independent bridge current scaling, mixed-decay flexibility, and on-chip 3.3-V regulation - making it optimal for space-constrained, dual-motor applications requiring configurable torque and autonomous fault handling without external support circuitry.

Availability

DRV8812RHDT is available at Aetrix Electronics and suitable for printers, video security cameras, and factory automation systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for DRV8812RHDT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in motor control IC design.

The DRV8812RHDT belongs to TI's high-voltage stepper and DC motor driver product line, engineered specifically for cost-sensitive, thermally constrained industrial and office automation systems requiring dual independent motor control with minimal external components.

FAQ

What is the maximum continuous output current rating for the DRV8812RHDT?

The DRV8812RHDT supports up to 1.6 A of continuous output current per H-bridge at 24 V and 25°C ambient temperature, assuming adequate heatsinking. This rating is thermally limited - actual achievable current depends on PCB copper area, airflow, and ambient temperature. At 85°C ambient, derating applies per the R_θJA = 35.8°C/W specification. The DRV8812RHDT must not exceed its absolute maximum junction temperature of 150°C.

How does the DRV8812RHDT implement current regulation for stepper motors?

The DRV8812RHDT regulates winding current using fixed-frequency (50 kHz) PWM chopping. It compares 5× the voltage across an external sense resistor (connected to ISENA/ISENB) against a reference voltage applied to AVREF/BVREF. The 2-bit AI0/AI1 and BI0/BI1 inputs scale the effective reference to achieve 100%, 71%, 38%, or 0% of full-scale current. A 3.75-µs blanking time prevents false triggering during MOSFET turn-on. This architecture enables precise microstepping control in the DRV8812RHDT.

What decay modes does the DRV8812RHDT support, and how are they selected?

The DRV8812RHDT supports three decay modes: slow decay (LS-FET recirculation), fast decay (H-bridge reversal), and mixed decay (75% fast + 25% slow). Selection is controlled solely by the DECAY pin: logic low = slow, open = mixed, logic high = fast. This single-pin configuration applies identically to both bridges. Mixed decay improves torque linearity in stepper applications by combining rapid current decay with efficient energy recovery - a key differentiator of the DRV8812RHDT.

Does the DRV8812RHDT include built-in protection features, and how are faults reported?

Yes, the DRV8812RHDT integrates overcurrent protection (OCP), thermal shutdown (TSD), and VM undervoltage lockout (UVLO). Each protection circuit independently disables its respective H-bridge and asserts the open-drain nFAULT pin low. Fault conditions persist until either the nRESET pin is pulsed low or VM is cycled. Unlike current-sense-based regulation, OCP uses dedicated analog circuitry independent of sense resistor value - ensuring robust fault detection even with resistor tolerance or layout variation in the DRV8812RHDT.

Can the DRV8812RHDT operate from a single 24-V supply, and what external components are mandatory?

Yes, the DRV8812RHDT operates from a single 8.2–45-V supply connected to both VMA and VMB pins. Mandatory external components include: two 0.1-µF ceramic capacitors (one each at VMA and VMB, rated for VM), one 0.47-µF ceramic capacitor at VMB for bulk decoupling, 0.01-µF and 0.1-µF flying capacitors for CP1/CP2/VCP, and two current sense resistors (e.g., 400 mΩ) connected between ISENA/ISENB and GND. The DRV8812RHDT also requires proper thermal connection of its PowerPAD™ to PCB copper for safe 1.6-A operation.