Monolithic Power Systems Inc. MPQ8632GL-4-Z

Overview

MPQ8632GL-4-Z from Monolithic Power Systems is a fully integrated 4A synchronous step-down DC/DC converter with 2.5V–18V input range, Constant-On-Time (COT) control, non-latch over-voltage protection, and 0.611V–13V adjustable output voltage. It delivers high efficiency in telecom power supplies, server point-of-load regulation, and flat-panel display bias rails using internal MOSFETs with 28 mΩ high-side and 16.4 mΩ low-side R_DS(ON) at 25°C.

For engineers reviewing the MPQ8632GL-4-Z datasheet, MPQ8632GL-4-Z pinout, MPQ8632GL-4-Z application, or MPQ8632GL-4-Z equivalent, key selection criteria include its 16-pin QFN 3mm×4mm package, programmable 200kHz–1MHz switching frequency via external resistor, soft-start timing control, power-good open-drain signal, and thermal shutdown at 150°C.

Technical Context

The MPQ8632GL-4-Z implements adaptive COT control without an external oscillator, using feed-forward compensation from the FREQ pin to maintain stable switching frequency across input voltage variation. Its internal 4.8V VCC LDO powers gate drivers and control logic, while bootstrap circuitry enables high-side N-channel MOSFET operation.

It operates in continuous-conduction mode (CCM) under heavy load and transitions to discontinuous-conduction mode (DCM) with skip-mode control at light load, achieving high efficiency across 0–4A output current. Protection includes non-latch over-current, over-voltage (120% V_FB threshold), and thermal shutdown with 25°C hysteresis.

Key Specifications

Pinout & Package

MPQ8632GL-4-Z uses a thermally enhanced 16-pin QFN package (3mm × 4mm, 0.5mm pitch) with exposed thermal pad. Pin 1 is marked by dot; top marking is "MP8632 E4".

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with MPQ8632GL-4-Z, MPQ8632GLE-6 offers higher current capacity in identical packaging for seamless scalability, while RTQ2134GSP-QA trades programmability and flexibility for automotive qualification and extended input voltage-making it unsuitable for cost-sensitive industrial or telecom use.

Availability

MPQ8632GL-4-Z is available at Aetrix Electronics and suitable for telecom infrastructure, server power management, flat-panel display subsystems, and distributed industrial power requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for MPQ8632GL-4-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, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ8632 family targets high-density, high-efficiency DC/DC conversion in space-constrained applications such as networking equipment, servers, and consumer displays-emphasizing integration, thermal robustness, and ease of layout.

FAQ

What is the minimum input voltage supported by MPQ8632GL-4-Z?

The MPQ8632GL-4-Z supports 2.5V minimum input when powered with an external 5V bias applied to the VCC pin, enabling compatibility with single-cell Li-ion or LiPo batteries. Without external bias, the minimum input is 4.5V due to internal VCC LDO requirements.

Can MPQ8632GL-4-Z operate with pre-biased output capacitors?

Yes, MPQ8632GL-4-Z supports pre-bias startup: it disables reverse current flow during initial turn-on, preventing output voltage collapse or damage to downstream circuitry when the output rail is already charged.

How is switching frequency set and stabilized across input voltage variation?

Switching frequency is set by a resistor between FREQ and VIN. The MPQ8632GL-4-Z uses feed-forward compensation-linking the ON-time timer directly to VIN-so frequency remains nearly constant despite input voltage changes, unlike traditional oscillator-based controllers.

What thermal derating applies above 25°C ambient?

With θ_JA = 46°C/W (QFN 3×4mm), maximum continuous power dissipation drops linearly: at 70°C ambient, PD_MAX = (150°C − 70°C)/46°C/W ≈ 1.74W. Layout improvements (thermal vias, copper area) can reduce effective θ_JA and extend usable current.

Is the power-good (PG) signal compatible with 3.3V logic systems?

Yes, PG is an open-drain output requiring an external pull-up. When pulled to 3.3V, it sinks ≥12mA at VOL ≤ 600mV, ensuring clean TTL/CMOS-compatible assertion and release with 2.5ms delay for stable regulation confirmation.

Does MPQ8632GL-4-Z require external compensation components?

No-its Constant-On-Time (COT) architecture eliminates the need for external Type-II or Type-III compensation networks. Stability is inherent and independent of output capacitor ESR, simplifying design and reducing component count.

What is the purpose of the AGND and PGND separation?

AGND serves as the quiet reference for feedback, soft-start, and internal comparators; PGND carries high di/dt return currents from MOSFETs and inductor. Separating them prevents noise coupling into regulation circuitry and maintains output accuracy under dynamic load.