Texas Instruments LM4570LQ/NOPB

Overview

LM4570LQ/NOPB from Texas Instruments is a single-supply, bridged (BTL) motor driver IC designed for bidirectional DC motor control in space-constrained portable electronics. It delivers 192 mA output current at 3V supply, features differential outputs VO1/VO2 for rapid voltage polarity reversal, and includes logic-controlled shutdown (/SD), internal reference (REF1), and rail-to-rail swing under load - enabling precise speed and direction control in mobile phone vibration motors.

For engineers reviewing the LM4570LQ/NOPB datasheet, LM4570LQ/NOPB pinout, LM4570LQ/NOPB application, or LM4570LQ/NOPB equivalent, key selection considerations include its 8-pin WQFN-NGP package thermal performance, 2.4–5.5V operating range, 2.4 ms turn-on time at 3V, and BTL architecture's ability to generate reverse-polarity braking pulses without dual supplies.

Technical Context

The LM4570LQ/NOPB implements a fully differential bridge output stage with complementary VO1 and VO2 terminals that both source and sink current, enabling true bipolar drive across the motor load. Its gain is set externally via RIN and RF per AVD = 2 × (RF/RIN), supporting configurable voltage amplification while maintaining BTL operation.

It integrates thermal shutdown and output short-circuit protection, operates with VDD referenced to GND only, and uses /SD to disable bias circuitry and force REF1 and outputs to GND. The device requires external 0.1 µF bypass on REF1 and 1 µF on VDD for stable operation, and its exposed DAP must be connected to GND for thermal management.

Key Specifications

Pinout & Package

The LM4570LQ/NOPB is housed in an 8-pin WQFN package (NGP0008A) with an exposed die attach paddle (DAP) for thermal conduction. The DAP must be soldered to a GND plane using multiple vias for effective heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar motor driver applications.

Compared with TB67H420FTG and DRV8837, the LM4570LQ/NOPB uniquely combines analog-input BTL drive, sub-1µA shutdown, integrated REF1, and WQFN thermal optimization - making it purpose-built for low-power, space-constrained haptic motor control where simplicity and efficiency are prioritized over raw current capability.

Availability

LM4570LQ/NOPB is available at Aetrix Electronics and suitable for mobile phone vibration systems, handheld game controller haptics, and wearable tactile alert modules requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for LM4570LQ/NOPB 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM4570LQ/NOPB belongs to TI's precision analog motor driver product line, engineered specifically for low-voltage, low-power haptic feedback applications in portable consumer devices where size, thermal efficiency, and analog control simplicity are essential.

FAQ

What is the function of the /SD pin on the LM4570LQ/NOPB?

The /SD pin on the LM4570LQ/NOPB is an active-low shutdown control input. When pulled low, it disables the internal amplifiers and bias circuitry, forces REF1 and both VO1/VO2 outputs to GND, and reduces quiescent supply current to 0.1 µA. For normal operation, /SD must be tied to VDD. This feature enables precise power gating in battery-powered devices using the LM4570LQ/NOPB.

Can the LM4570LQ/NOPB drive a motor in both directions using a single supply?

Yes, the LM4570LQ/NOPB drives a motor bidirectionally using only a single supply by leveraging its bridged (BTL) output architecture. VO1 and VO2 operate differentially: when VO1 > VO2, the motor spins clockwise; when VO1 < VO2, it spins counter-clockwise. Polarity reversal is achieved by varying the IN voltage relative to REF1 - eliminating need for dual supplies or external H-bridge transistors in the LM4570LQ/NOPB design.

What is the recommended PCB layout practice for the exposed DAP on the LM4570LQ/NOPB?

The exposed DAP on the LM4570LQ/NOPB must be soldered to a solid GND plane on the PCB's outer layer using at least four 0.3-mm vias thermally and electrically connecting to an unbroken inner-layer GND plane. Plating and solder-mask tenting of vias is required to ensure low thermal resistance (θJA = 140°C/W). Failure to properly connect the DAP will cause thermal overload and premature device failure under sustained 192 mA load in the LM4570LQ/NOPB.

Does the LM4570LQ/NOPB require external gain-setting resistors?

Yes, the LM4570LQ/NOPB requires external resistors RIN and RF to set its differential gain per AVD = 2 × (RF/RIN). These resistors connect between IN and REF1 (RIN) and between VO1 and REF1 (RF), forming a feedback network that defines output voltage swing relative to input. Gain configuration is mandatory - the LM4570LQ/NOPB does not operate with fixed internal gain and cannot function without these external components.

What is the maximum continuous output current the LM4570LQ/NOPB can deliver at 3V supply?

The LM4570LQ/NOPB delivers up to 192 mA continuous output current into a 30 Ω load at VDD = 3V, as specified in the Electrical Characteristics table for TA = 25°C. This rating assumes proper thermal management via the exposed DAP and ambient temperature within −40°C to +85°C. Exceeding this current or operating above 85°C ambient may trigger thermal shutdown, limiting sustained output in the LM4570LQ/NOPB.