Monolithic Power Systems Inc. MP8040DN-LF

Overview

MP8040DN-LF from Monolithic Power Systems is a high-current, high-frequency half-bridge power driver IC integrating matched 100mΩ N-channel MOSFETs, delivering ±9A peak and ±4.25A continuous output current with up to 1.2MHz switching frequency. It operates from 7.5V–25V input, features 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 datasheet, MP8040DN-LF pinout, MP8040DN-LF application, or MP8040DN-LF equivalent, key selection criteria include its true 2-quadrant sourcing/sinking capability, bootstrap-based high-side drive architecture, integrated protection thresholds, and SOIC-8N exposed-pad thermal performance.

Technical Context

The MP8040DN-LF implements a self-contained half-bridge gate driver with internal high-side and low-side N-MOSFETs, controlled by a single PWM input. Its bootstrap supply (BS) enables high-side gate drive above SP voltage, requiring an external 0.1µF capacitor between BS and SW.

It integrates cycle-by-cycle current limiting on both switches, thermal shutdown with 20°C hysteresis (trip at 160°C, restart at 140°C), UVLO on SP (6.5V threshold), and a 2.5µA shutdown mode activated via SHDN pin. Fault detection asserts open-drain FLT low for overcurrent, overtemperature, or UVLO events.

Key Specifications

Pinout & Package

MP8040DN-LF uses an SOIC-8N package with exposed thermal pad (connected internally to GND/Pin 4), offering θ_JA = 50°C/W and θ_JC = 8°C/W on 1"² 1oz copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP8040DN-LF, MP8042DN-LF adds channel independence at the cost of board area and pin count, while IR2104S trades integration for voltage scalability-neither offers identical current density, thermal performance, or protection integration in the 7.5–25V range.

Availability

MP8040DN-LF is available at Aetrix Electronics and suitable for Class D audio amplifiers, BLDC motor controllers, and half-bridge DC-DC regulators requiring stable component supply, consistent thermal performance, and production-ready protection features.

Supply support for MP8040DN-LF 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 power driver product line, engineered for compact, thermally efficient half-bridge implementations in audio, motor, and power conversion systems where integration, reliability, and fast switching are critical.

FAQ

What is the maximum allowable voltage on the SP pin?

The absolute maximum SP voltage is 28V, but the recommended operating range is 7.5V to 24V. Operation above 24V risks exceeding internal MOSFET breakdown limits and reduces long-term reliability-even if within absolute max ratings-due to increased conduction and switching losses.

How is the bootstrap capacitor sized for reliable high-side drive?

A minimum 0.1µF X7R ceramic capacitor rated ≥16V must be placed between BS and SW, with short, low-inductance traces. For 1.2MHz operation and 9A peak current, 0.22µF is recommended to maintain ≥4.5V bootstrap voltage under worst-case duty cycle and load conditions.

Does MP8040DN-LF support 100% duty cycle operation?

No-it cannot sustain 100% high-side conduction due to bootstrap capacitor discharge. The internal charge pump refreshes BS every 300µs, limiting practical maximum duty cycle to 99.5% at 3.3kHz, as verified in the datasheet's electrical characteristics table.

What happens when FLT goes low?

FLT asserts low (open-drain) when any fault condition occurs: output current exceeds 9A, junction temperature exceeds 160°C, or SP falls below 6.5V. Upon fault, both MOSFETs turn off, SW enters high-impedance state, and DRV drops to 0V-requiring external reset or SHDN toggle to resume operation.

Can MP8040DN-LF 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 FET body diode and channel; no external diodes are needed for standard inductive loads like motors or speakers.

Is the exposed thermal pad electrically connected?

Yes-the exposed pad on the SOIC-8N package is internally connected to Pin 4 (GND). It must be soldered to a dedicated PCB ground plane with ≥4 thermal vias (0.3mm diameter) to achieve specified θ_JA = 50°C/W and prevent thermal derating above 85°C ambient.

What is the propagation delay from PWM to SW edge?

The typical PWM-to-SW delay is 70ns for both rising and falling edges, measured at VSP = 12V, TA = +25°C. This delay remains stable across input voltage (7.5–24V) and temperature (–40°C to +85°C), enabling precise timing in closed-loop motor or audio systems.