Monolithic Power Systems Inc. MPM3682GRE

Overview

MPM3682GRE from Monolithic Power Systems is a fully integrated 10A synchronous step-down power module with integrated inductor, input/output capacitors, and control circuitry in a QFN-57 (12×12×4 mm) package. It delivers regulated output from 0.65 V to 5 V across 4.5–18 V input (or 2.5–18 V with external 5 V bias), uses adaptive Constant-On-Time (COT) control for ultrafast transient response, and supports programmable soft-start (default 3 ms), frequency tuning (200 kHz–1 MHz), and pre-bias startup - deployed in telecom base stations and server VRMs.

For engineers reviewing the MPM3682GRE datasheet, MPM3682GRE pinout, MPM3682GRE application, or MPM3682GRE equivalent, key selection considerations include its integrated power stage architecture, dual-bias operation mode (internal LDO vs. external 5 V), non-latch OCP/OVP/thermal shutdown, PG open-drain signaling with 2.5 ms delay, and DC/AC trimming capability for precision output regulation.

Technical Context

The MPM3682GRE implements adaptive COT control with input-voltage feed-forward, enabling stable operation across wide VIN ranges without external compensation. Its internal 430 kΩ frequency-set resistor yields ~500 kHz at 1.2 VOUT, scaling with output voltage per equation-based timing.

It features dual current-limit protection: valley-current detection during LS-FET conduction and negative-current limiting to prevent reverse inductor current; both trigger hiccup-mode recovery. The internal 4.8 V LDO powers control logic but can be disabled via external 5 V bias to extend low-input operation down to 2.5 V while improving light-load efficiency.

Key Specifications

Pinout & Package

MPM3682GRE is housed in a thermally enhanced QFN-57 package (12 mm × 12 mm × 4 mm) with exposed thermal pad (GND-connected) and 57 terminals. Pin layout supports high-current routing: multiple parallel VIN, GND, SW, and VOUT pins minimize IR drop and inductance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current integrated buck converter applications.

Compared with MPM3682GRE, MPM3683GRE offers lower thermal resistance and extended lifetime support, while TPSM84624IRKR provides TI-specific design continuity but lacks trimming and bias-flexibility - making MPM3682GRE optimal for cost-sensitive, high-transient telecom upgrades where legacy compatibility is acceptable.

Availability

MPM3682GRE is available at Aetrix Electronics and suitable for telecom base stations, server VRMs, and flat-panel display power systems requiring stable component supply and proven field reliability in high-volume production.

Supply support for MPM3682GRE 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, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPM368x series targets high-density, high-efficiency DC/DC conversion in infrastructure equipment - designed to replace discrete buck solutions with minimal external components while maintaining enterprise-grade thermal and reliability specs.

FAQ

What is the recommended PCB layout for thermal management of MPM3682GRE?

Use a 4-layer board with dedicated inner ground and power planes; connect the exposed thermal pad to a solid GND copper area ≥200 mm² using ≥9 thermal vias (0.3 mm diameter, 0.6 mm pitch); route VIN/VOUT traces ≥2 mm wide with 2 oz copper to limit temperature rise below 30 °C at 10 A.

Can MPM3682GRE operate with an input voltage below 4.5 V?

Yes - when a clean 5 V external bias is applied to the VCC pin, the internal LDO is disabled and VIN can be as low as 2.5 V; this configuration improves light-load efficiency by ~5% but requires separate 5 V rail generation and careful noise isolation from VCC.

How does the AC_trim pin improve transient performance?

The AC_trim pin connects to VOUT through a small capacitor (typically 10–100 pF) to inject derivative feedback into the COT comparator, accelerating response to fast load steps by anticipating output droop before it occurs - reducing peak deviation by up to 40% compared to no AC trim.

What happens during pre-bias startup, and how is it implemented?

When VOUT is pre-charged, the MPM3682GRE holds both HS- and LS-FETs off until the SS capacitor voltage exceeds the sensed FB voltage; this prevents reverse current flow and ensures monotonic ramp-up - critical for hot-swap and redundant power systems.

Is MPM3682GRE pin-compatible with MPM3683GRE?

No - although both use QFN-57 packages, MPM3683GRE has revised pin mapping (e.g., relocated FREQ and BST pins) and different top marking; board-level replacement requires layout revision and validation of thermal and EMI performance under identical load conditions.

What is the maximum allowable output capacitance for stable operation?

The MPM3682GRE supports unlimited ceramic output capacitance due to COT control stability - tested with up to 10×47 µF (470 µF total) without oscillation; however, excessive capacitance (>1000 µF) may extend soft-start time beyond system requirements and increase inrush stress on input capacitors.

Does MPM3682GRE support synchronization to an external clock?

No - the MPM3682GRE lacks an external clock sync input; frequency is set only via internal resistor or external R_FREQ between FREQ> and VIN; for synchronized multi-phase operation, use MPM3695 or discrete controller + DrMOS solutions.