STMicroelectronics L6227QTR

Overview

L6227QTR from STMicroelectronics is a DMOS dual full-bridge motor driver IC with integrated PWM current controllers, designed for bipolar stepper and dual/quad DC motor control. It operates from 8–52 V supply, delivers 2.8 A peak (1.4 A DC) per bridge, features 0.73 Ω typical R_DS(on) at 25 °C, supports up to 100 kHz switching, and includes non-dissipative overcurrent protection and thermal shutdown.

For engineers reviewing the L6227QTR datasheet, L6227QTR pinout, L6227QTR application, or L6227QTR equivalent, key selection considerations include its dual independent constant t_OFF PWM current regulation, slow-decay synchronous rectification, cross-conduction protection, and VFQFPN32 5 mm × 5 mm package with exposed thermal pad.

Technical Context

The L6227QTR integrates two fully independent power bridges, each with N-channel high-side and low-side DMOS transistors and intrinsic fast freewheeling diodes. Each bridge employs a dedicated constant off-time PWM current controller using external RC networks on RCA/RCB pins to set t_OFF, with blanking time (1 µs) to suppress diode reverse-recovery spikes.

Logic inputs (IN1A/IN2A/IN1B/IN2B) are TTL/CMOS compatible with hysteresis (0.25–0.5 V), while ENA/ENB enable pins double as open-drain fault outputs tied to internal overcurrent and thermal protection transistors. The charge pump (VCP output, ~600 kHz, 10 V amplitude) generates VBOOT for high-side gate drive, requiring external 220 nF bootstrap and 10 nF pump capacitors.

Key Specifications

Pinout & Package

Package: VFQFPN32 (5 mm × 5 mm, 0.5 mm pitch), with exposed thermal pad connected to GND for enhanced thermal dissipation (R_th(JA) = 42 °C/W on specified PCB layout).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TB6612FNG and DRV8876PWPR, the L6227QTR uniquely combines dual independent constant t_OFF PWM control, 52 V operation, non-dissipative OCP, and slow-decay rectification-making it the only option for high-voltage, high-precision bipolar stepper or dual-DC motor systems requiring minimal external components and thermal resilience.

Availability

L6227QTR is available at Aetrix Electronics and suitable for industrial automation, medical infusion pumps, and automotive HVAC systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L6227QTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in power management, motor control, and automotive-grade ICs with broad industrial qualification.

The L6227QTR belongs to ST's BCDmultipower motor driver product line, engineered for high-efficiency, high-voltage motor control in space-constrained applications where integration, thermal performance, and fault resilience are critical.

FAQ

What is the purpose of the VCP pin on the L6227QTR?

The VCP pin outputs a 600 kHz, 10 V amplitude square wave that drives an external charge pump circuit (CP capacitor and two 1N4148 diodes) to generate the VBOOT voltage. This bootstrapped supply enables gate drive for the high-side N-channel MOSFETs above the VS rail, eliminating the need for a separate high-voltage bias supply.

How does the non-dissipative overcurrent protection work without a sense resistor?

The L6227QTR embeds precision current-mirror circuitry within each high-side DMOS transistor, delivering a scaled replica (1/n) of the output current to internal comparators. When this mirrored current exceeds the 2.8 A threshold, the EN pin is actively pulled low via an internal 4 mA open-drain MOSFET-detecting overloads without external shunts or associated I²R losses.

Can the L6227QTR drive a unipolar stepper motor?

No-the L6227QTR is specifically designed for bipolar stepper motors and dual/quad DC motors. Its dual full-bridge topology requires four terminals per motor winding and cannot interface with the center-tapped configuration of unipolar steppers. For unipolar applications, a dedicated unipolar driver or discrete transistor array is required.

What is the minimum recommended copper area for the exposed thermal pad on the VFQFPN32 package?

STMicroelectronics specifies a minimum top-side copper area of 0.5 cm² connected to GND, plus a 6 cm² ground plane on the bottom layer, linked by 18 via holes (9 under the IC). This layout achieves R_th(JA) = 42 °C/W; reducing copper area increases junction temperature and risks thermal shutdown at rated load.