Monolithic Power Systems Inc. MPQ8636GV-20-P

Overview

MPQ8636GV-20 from Monolithic Power Systems is a fully integrated, synchronous step-down DC/DC converter delivering 20A output current with 4.5V–18V input range, 0.611V–13V adjustable output, and Constant-On-Time (COT) control for ultrafast transient response in telecom and server power rails.

For engineers reviewing the MPQ8636GV-20 datasheet, MPQ8636GV-20 pinout, MPQ8636GV-20 application, or MPQ8636GV-20 equivalent, key selection factors include its 25-pin QFN (5×4mm) package, non-latch OCP/OVP/thermal shutdown, programmable 200kHz–1MHz switching frequency via FREQ pin, and pre-bias start-up capability for distributed power systems.

Technical Context

The MPQ8636GV-20 implements adaptive COT control without an external oscillator, using feed-forward compensation from the IN pin to the FREQ pin to maintain stable switching frequency across input voltage variation. Its internal high-side and low-side MOSFETs feature R_DS(ON) of 9.9mΩ and 2.4mΩ respectively, enabling high efficiency across load range.

It operates exclusively in continuous conduction mode (CCM), supports monotonic pre-bias startup, and uses an open-drain PG signal with 2.5ms delay and 87–94% V_FB rising threshold to indicate regulated output. Protection includes non-latch valley-current OCP (20–30A), negative-current limiting (−6.5A to −4.5A), and 120% non-latch OVP with hiccup recovery.

Key Specifications

Pinout & Package

MPQ8636GV-20 is housed in a thermally enhanced 25-pin QFN package (5mm × 4mm, 0.5mm pitch) with exposed thermal pad (PGND-connected) for efficient heat dissipation in high-current applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ8636HGV-20, the MPQ8636GV-20 offers higher OVP trip margin (130% vs. 120%) and valley-current hiccup recovery, making it more robust in unregulated input environments; versus TPS546B24A, it trades digital features for smaller footprint, lower BOM cost, and analog simplicity in fixed-function power rails.

Availability

MPQ8636GV-20 is available at Aetrix Electronics and suitable for telecom base stations, server VR13 core rails, and flat-panel display logic supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MPQ8636GV-20 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 MPQ8636 series belongs to MPS's high-current integrated buck converter product line, engineered specifically for space-constrained, high-efficiency point-of-load applications in networking, computing, and consumer electronics where minimal external components and fast transient response are critical.

FAQ

What is the maximum allowable junction temperature for continuous operation?

The MPQ8636GV-20 has a maximum junction temperature of +125°C for continuous operation, with thermal shutdown triggered at +150°C and 25°C hysteresis. Derating is required above +125°C ambient; thermal performance depends on PCB copper area, layer count, and airflow-typical θ_JA is 38°C/W on a 4-layer board.

Can the MPQ8636GV-20 operate with ceramic output capacitors without external ramp compensation?

No-ceramic capacitors have very low ESR, which reduces the natural V_FB ripple slope needed for COT stability. An external ramp compensation network (R4/C4) must be added per Equation 4–7 in the datasheet to ensure stable PWM operation and avoid subharmonic oscillation.

How does the FREQ pin determine switching frequency, and what resistor value sets 500kHz?

The FREQ pin uses feed-forward from IN to set ON-time: τ_ON ≈ 0.4 × (V_IN − 6.1)/R_FREQ (ns). For 500kHz at V_IN = 12V, R_FREQ ≈ 453kΩ yields ~250ns ON-time. Frequency remains stable across VIN variation due to feed-forward architecture.

Is the MPQ8636GV-20 compatible with pre-biased outputs, and how does it behave during startup?

Yes-it supports monotonic pre-bias startup. If V_OUT is already present, the IC disables both HS and LS switches until the SS capacitor voltage exceeds the sensed FB voltage; then it ramps output smoothly without reverse current or overshoot.

What is the purpose of the AGND and PGND separation, and how should they be routed?

AGND serves as the quiet reference for feedback, soft-start, and control circuits; PGND carries high di/dt return currents from power switches. They must connect at a single point near the IC's thermal pad-never daisy-chained-to prevent noise coupling into the FB loop and avoid regulation instability.

Does the MPQ8636GV-20 support forced PWM mode or DCM operation?

No-it operates exclusively in continuous conduction mode (CCM) across all loads. Light-load efficiency is maintained via low quiescent current (1μA shutdown, 1mA typical operating), but it does not enter discontinuous mode or support external mode selection.

What is the minimum output voltage achievable, and what limits it?

The minimum output voltage is 0.611V, set by the internal 611mV reference voltage. This limit is fixed by the bandgap reference design and cannot be reduced further-even with zero-resistance bottom resistor-due to comparator input offset and reference tolerance.