Monolithic Power Systems Inc. MPQ8626GD-Z

Overview

MPQ8626GD-Z from Monolithic Power Systems is a fully integrated, synchronous step-down DC/DC converter delivering up to 6A output current with adjustable current limit, 0.6V–6V output voltage range, and selectable 600/1100/2000kHz switching frequency-designed for high-efficiency point-of-load regulation in telecom and server power rails.

For engineers reviewing the MPQ8626GD-Z datasheet, MPQ8626GD-Z pinout, MPQ8626GD-Z application, or MPQ8626GD-Z equivalent, key selection factors include its adaptive constant-on-time (COT) control for ultrafast transient response, programmable soft-start (2.2ms minimum), PGOOD open-drain status signal with 1ms delay, and QFN-14 (2mm×3mm) thermal performance (θJB = 6.8°C/W).

Technical Context

The MPQ8626GD-Z implements an internally compensated adaptive constant-on-time (COT) control architecture that maintains stable regulation across wide input (4V–16V) and output (0.6V–6V) ranges without external compensation. It supports both forced continuous conduction mode (CCM) and pulse-skip mode (PSM), selected via MODE pin resistor configuration.

Its valley-current sensing uses internal MOSFET R_DS(ON) (HS: 22.6mΩ, LS: 8.1mΩ @25°C) and a programmable CS pin with 40µA/A mirroring ratio to set over-current protection thresholds from 4A to 8A. Protection includes non-latching OCP, OVP (116% V_REF trip), UVP (80% V_REF), OTP (160°C shutdown), and pre-bias start-up capability.

Key Specifications

Pinout & Package

MPQ8626GD-Z is housed in a thermally enhanced QFN-14 package (2mm × 3mm, 0.5mm pitch) with exposed PGND pad for optimal heat dissipation and EMI control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ8623GD-Z, the MPQ8626GD-Z delivers 50% higher current in identical footprint and adds programmable frequency selection; versus RTQ2132BGQW-Z, it eliminates compensation network design effort but trades off some flexibility in multi-phase synchronization.

Availability

MPQ8626GD-Z is available at Aetrix Electronics and suitable for telecom infrastructure, server power distribution, and high-end consumer electronics requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MPQ8626GD-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 MPQ8626 belongs to MPS's high-efficiency synchronous buck converter product line, engineered specifically for compact, high-current point-of-load applications in datacenter, networking, and consumer electronics where thermal density and transient response are critical.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MPQ8626GD-Z is stable with zero-ESR ceramic capacitors only. Minimum recommended output capacitance is 22µF (X5R/X7R, 6.3V rating), placed within 3mm of FB and PGND pins. Larger values (e.g., 47–100µF) improve load transient undershoot but are not required for stability.

Can the MPQ8626GD-Z operate without an external VCC bias supply?

Yes. The MPQ8626GD-Z operates with internal VCC bias across its full 4V–16V input range. An external 3.3V VCC bias is optional and only needed if VIN drops below 4V or to reduce startup time under marginal input conditions.

How is the current limit threshold set, and what tolerance should be expected?

The current limit is set by connecting a precision resistor (RCS) from CS to AGND. Using Table 2 values (e.g., 4.87kΩ for 6A), the typical trip accuracy is ±5% over temperature and line. The internal 1.2V OCP threshold and 40µA/A mirroring ratio ensure consistent cycle-by-cycle valley-current limiting.

Does the MPQ8626GD-Z support remote output voltage sensing?

No. The MPQ8626GD-Z does not include dedicated remote sense pins. Output voltage regulation relies on local FB connection. For improved load regulation under high-current PCB traces, place the feedback divider as close as possible to the output capacitor and use Kelvin connections to minimize IR drop errors.

What happens during input UVLO, and how does PGOOD behave?

When VIN falls below 2.25V (rising threshold), the device shuts down and discharges TRK/REF. PGOOD is actively clamped to ~0.7V (not open-drain) during UVLO or power failure, providing unambiguous fault signaling even when VCC is lost-enabling robust system-level power sequencing.

Is the MODE pin compatible with standard logic voltage levels?

No. MODE is a resistor-programmed configuration pin-not a digital logic input. It must be pulled to AGND or VCC through precision resistors (e.g., 30.1kΩ ±20%) per Table 1. Direct connection to 3.3V or 0V will force undefined operation and may cause erratic frequency or mode behavior.

What thermal derating applies above +85°C ambient?

With standard 2-layer PCB (2oz Cu, 1in² exposed PGND pad), output current derates linearly from 6A at +85°C to ~4.5A at +125°C ambient. Derating follows θJB = 6.8°C/W: each 10°C rise above 85°C reduces max I_OUT by ~0.25A to maintain T_J ≤125°C.