Monolithic Power Systems Inc. MPQ8633BGLE-Z

Overview

MPQ8633BGLE-Z from Monolithic Power Systems is a fully integrated, high-frequency synchronous buck converter delivering up to 20A output current with 0.6V–5.5V adjustable output voltage, 600–1000kHz programmable switching frequency, and differential remote sensing for precision regulation in point-of-load applications.

For engineers reviewing the MPQ8633BGLE-Z datasheet, MPQ8633BGLE-Z pinout, MPQ8633BGLE-Z application, or MPQ8633BGLE-Z equivalent, this device supports pre-bias start-up, output voltage tracking via TRK/REF, adaptive COT control for ultrafast transient response, and non-latch OCP with hiccup recovery-critical for telecom, server, and GPU power rails.

Technical Context

The MPQ8633BGLE-Z implements an internally compensated constant-on-time (COT) control architecture with adaptive ramp compensation, enabling stable operation with zero-ESR MLCC output capacitors across full input (4V–16V) and output (0.6V–5.5V) ranges. Its valley-current sensing via CS pin enables cycle-by-cycle over-current protection with programmable trip threshold (1.15–1.25V).

It integrates dual MOSFETs with R_DS(ON) of 8.6mΩ (HS) and 2.5mΩ (LS), supports forced CCM or pulse-skip light-load modes via MODE pin resistor selection, and features differential remote sense (FB/RGND) with 0.5% reference voltage accuracy over 0°C–70°C junction temperature.

Key Specifications

Pinout & Package

MPQ8633BGLE-Z is housed in a thermally enhanced QFN-21 (3mm × 4mm) package with exposed PGND paddle for low-impedance heat dissipation and 0.4mm pitch. The package supports reflow soldering per JEDEC J-STD-020 and achieves θ_JB = 8°C/W on 2-layer 1oz copper PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ8633DGLE-Z, the MPQ8633BGLE-Z trades extended temperature rating for lower cost and identical electrical performance at ≤125°C; versus TPS546D24RVFT, it offers smaller footprint and analog tracking at the expense of digital configurability and higher current capacity.

Availability

MPQ8633BGLE-Z is available at Aetrix Electronics and suitable for telecom base stations, cloud-computing server boards, and high-end GPU power delivery requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for MPQ8633BGLE-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 MPQ8633B product line targets high-current, high-efficiency point-of-load conversion in space-constrained infrastructure equipment, emphasizing thermal robustness, fast transient response, and analog flexibility over digital complexity.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MPQ8633BGLE-Z is stable with zero-ESR ceramic capacitors only. MPS recommends ≥220μF total output capacitance using X7R/X5R MLCCs (e.g., ten 22μF/6.3V devices) placed close to SW and PGND pins. Bulk electrolytic caps are not required, reducing board area and improving reliability.

Can the MPQ8633BGLE-Z operate with an input voltage below 4V?

Yes-when biased with an external 3.3V supply applied to VCC (Pin 19), the MPQ8633BGLE-Z supports input voltages as low as 2.7V. This enables use in battery-powered or low-voltage intermediate bus applications, provided VCC_EXT remains within 3.12–3.6V and is well-decoupled.

How does the TRK/REF pin affect soft-start behavior?

When TRK/REF is used for voltage tracking, soft-start is disabled-the output follows the TRK/REF voltage ramp directly. If TRK/REF is used solely for soft-start, a capacitor (e.g., 1nF) between TRK/REF and RGND sets t_SS ≈ 1ms; adding CSS2 ≥22nF extends ramp time per Equation 2 in the datasheet.

What happens during a short-circuit event at the output?

Upon short-circuit detection (CS voltage exceeding 1.2V), the MPQ8633BGLE-Z enters hiccup mode after 3ms: it disables switching for ~11ms, then attempts auto-restart. This limits average power dissipation to <1W during fault, preventing thermal runaway while allowing automatic recovery when fault clears.

Is the PGOOD signal functional when VIN is absent?

Yes-PGOOD remains active-clamped at ~0.7V when VIN fails, due to internal clamp circuitry. This provides unambiguous power-failure indication even during brown-out conditions, enabling safe system shutdown without external supervision circuits.

How is thermal performance affected by PGND pad soldering?

The QFN-21 PGND pad (Pins 11–18 + thermal paddle) accounts for >80% of heat transfer. Inadequate solder coverage (<70%) or missing thermal vias increases θ_JB beyond 8°C/W, risking thermal shutdown at <15A load. MPS recommends 9×0.3mm vias filled with solder connecting paddle to inner ground plane.