Monolithic Power Systems Inc. MP8040DN-LF-Z

Overview

MP8040DN-LF-Z from Monolithic Power Systems is a high-current, high-frequency half-bridge power driver IC integrating matched 0.1Ω N-channel MOSFETs, delivering ±9A peak and ±4.25A continuous output current with up to 1.2MHz switching frequency, wide 7.5V–25V input range, and integrated cycle-by-cycle current limiting, thermal shutdown (160°C), under-voltage lockout, and active-low fault flag - used in Class D audio amplifiers and motor drivers.

For engineers reviewing the MP8040DN-LF-Z datasheet, MP8040DN-LF-Z pinout, MP8040DN-LF-Z application, or MP8040DN-LF-Z equivalent, key selection considerations include bootstrap gate drive architecture, true 2-quadrant sourcing/sinking capability, 70ns PWM-to-SW propagation delay, 2.5µA shutdown current, and SOIC-8N exposed-pad thermal performance for high-power density designs.

Technical Context

The MP8040 operates as a logic-controlled half-bridge driver with internal high-side and low-side N-MOSFETs, using bootstrap capacitor charging (via BS–SW) to enable high-side gate drive above SP voltage. Dead time is fixed at ~40ns (falling) and ~20ns (rising) to prevent shoot-through.

It implements analog current limiting on both switches, thermal shutdown with 20°C hysteresis (trip at 160°C, restart at 140°C), and under-voltage protection on SP (threshold ~6.5V). Fault detection asserts open-drain FLT low for overcurrent, overtemperature, or UVLO events.

Key Specifications

Pinout & Package

MP8040DN-LF-Z uses an SOIC-8N package with exposed thermal pad (connected to Pin 4/GND), offering θ_JA = 50°C/W and θ_JC = 8°C/W on 1"² 1oz copper - optimized for high-power dissipation in space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar half-bridge driver applications.

Compared with IR21844SPBF and LM5109BMAX/NOPB, MP8040DN-LF-Z delivers higher integration (MOSFETs + protection), tighter thermal management (exposed pad), and application-ready features (FLT, UVLO, 2.5µA shutdown) for 7.5–25V, ±9A systems - reducing BOM count and layout complexity.

Availability

MP8040DN-LF-Z is available at Aetrix Electronics and suitable for Class D audio amplifiers, brushed DC motor drivers, and high-frequency DC-DC buck-boost converters requiring stable component supply, consistent thermal performance, and production-ready protection features.

Supply support for MP8040DN-LF-Z 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, headquartered in Kirkland, WA, with global design and support operations.

The MP8040 belongs to MPS's high-current half-bridge driver product line, designed specifically for compact, efficient, and robust power conversion in audio, motor control, and lighting applications where integration, protection, and thermal reliability are critical.

FAQ

What is the maximum allowable voltage on the BS pin relative to SW?

The absolute maximum BS-to-SW voltage is +6V. Exceeding this risks damaging the internal bootstrap diode and high-side gate driver. A minimum 0.1µF ceramic capacitor rated for ≥16V must be placed between BS and SW, with low-ESR and short PCB traces to maintain voltage stability during high-frequency switching.

How does the MP8040 handle shoot-through prevention?

The MP8040 embeds fixed dead-time circuitry: ~20ns during rising edge and ~40ns during falling edge of SW transitions. This ensures both high-side and low-side MOSFETs are simultaneously off during switching transitions, eliminating shoot-through current without requiring external timing components or controller-level dead-time insertion.

Can MP8040DN-LF-Z drive inductive loads without external freewheeling diodes?

Yes - the integrated N-MOSFETs provide synchronous rectification paths. During low-side conduction, current recirculates through the low-side MOSFET body diode and channel; during high-side conduction, the low-side MOSFET is actively controlled to clamp inductive kickback. No external diodes are required for standard inductive loads like motors or speakers.

What is the recommended PCB layout practice for the exposed thermal pad?

The exposed pad on the SOIC-8N package must be soldered to a solid copper thermal pad connected to Pin 4 (GND) with ≥4 thermal vias (0.3mm diameter, spaced ≤1.2mm apart) to an internal or bottom-layer ground plane. This achieves the specified θ_JC = 8°C/W and prevents thermal derating above 4.25A continuous operation.

Does the FLT pin require a pull-up resistor, and if so, what value?

Yes - FLT is an open-drain output and requires an external pull-up resistor. The datasheet specifies connection to DRV (5V nominal) via a 100kΩ resistor. For microcontroller interfacing, a 10kΩ pull-up to 3.3V or 5V is acceptable, ensuring logic-high level meets MCU input threshold while limiting fault-current sink to <100µA.

Is the MP8040DN-LF-Z RoHS-compliant and halogen-free?

Yes - the "-LF" suffix denotes lead-free and RoHS-compliant construction. Monolithic Power Systems certifies MP8040DN-LF-Z as fully compliant with EU RoHS Directive 2011/65/EU and halogen-free per IEC 61249-2-21, with material declarations available upon request through Aetrix Electronics' compliance portal.

What happens to the SW node during thermal shutdown?

During thermal shutdown, both high-side and low-side MOSFETs turn off, placing SW in high-impedance (Hi-Z) state. The FLT pin is asserted low, and the internal 5V regulator powering DRV collapses - causing DRV voltage to drop to 0V. Recovery occurs automatically only after die temperature falls below 140°C, restoring normal operation without external reset.