Monolithic Power Systems Inc. MPQ4456GQT-P

Overview

MPQ4456GQT-P from Monolithic Power Systems is an industrial-grade, non-synchronous step-down DC/DC converter with integrated 300mΩ high-side MOSFET, delivering 1A output current across a 3.8V–36V input range, operating at up to 4MHz switching frequency, and featuring 120µA quiescent current for battery-powered automotive and industrial power systems.

For engineers reviewing the MPQ4456GQT-P datasheet, MPQ4456GQT-P pinout, MPQ4456GQT-P application, or MPQ4456GQT-P equivalent, key selection criteria include programmable 4MHz operation, extended PWM mode for low-noise light-load performance, internal soft-start, 0.8V feedback reference, and TQFN-10 (3mm × 3mm) thermal-enhanced package with exposed pad.

Technical Context

The MPQ4456GQT-P implements fixed-frequency peak-current-mode control with internal 0.8V reference and transconductance error amplifier (25–95µA/V), enabling fast transient response and stable loop compensation via external RC network on COMP pin. Its 80ns minimum on-time and 100ns minimum off-time constrain duty-cycle range at high frequencies.

It integrates bootstrap charging circuitry for the high-side driver, requiring external BST–SW capacitor and supporting operation up to 36V input; UVLO (2.6V/3.0V hysteresis), thermal shutdown (150°C/135°C hysteresis), and precision enable threshold (1.2V/1.5V) ensure robust system-level protection in harsh environments.

Key Specifications

Pinout & Package

MPQ4456GQT-P is housed in a thermally enhanced 10-pin TQFN package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad on underside for PCB-level heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4456GQT-P, MP2451DT-LF-Z trades output capability and frequency flexibility for lower cost and simpler layout, while LM61480RQWR offers higher integration and efficiency at the expense of size, BOM count, and design overhead - making MPQ4456GQT-P optimal for compact, 1A industrial/battery applications needing 4MHz EMI control.

Availability

MPQ4456GQT-P is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power rails, and battery-powered telematics requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MPQ4456GQT-P 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 core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MPQ4456 belongs to MPS's industrial-grade buck converter product line, designed specifically for ruggedized power delivery in automotive, factory automation, and infrastructure equipment where wide input range, low IQ, and high-frequency operation are mandatory.

FAQ

What is the maximum recommended input voltage for reliable 4MHz operation?

The MPQ4456GQT-P supports 4MHz switching only up to 12V input per manufacturer characterization; above 12V, switching frequency must be reduced (e.g., to 2MHz at ≤24V) to maintain minimum on-time margin and avoid pulse skipping or instability.

Can the MPQ4456GQT-P operate without an external bootstrap diode?

Yes - the MPQ4456GQT-P uses internal bootstrap charging via the BST–SW capacitor and does not require an external bootstrap diode; however, proper capacitor placement (0.1µF ceramic directly between BST and SW pins) and adequate VIN–VOUT headroom are essential for reliable high-duty-cycle operation.

How is output voltage accuracy affected by resistor divider tolerance?

With a typical FB reference of 0.796V ±2.5%, output voltage error is dominated by resistor ratio tolerance; using 1% R1/R2 yields ±1.5% total VOUT error at room temperature, while 0.1% resistors reduce this to ±0.5% - critical for precision analog subsystems.

Does the MPQ4456GQT-P support synchronous rectification?

No - the MPQ4456GQT-P is a non-synchronous buck converter requiring an external Schottky diode (e.g., B340A-13-F) connected from SW to GND; synchronous versions like MPQ4470 offer higher efficiency but lack the same 4MHz capability and industrial temp grade.

What thermal derating applies when using the exposed pad without thermal vias?

Without ≥6 thermal vias (0.3mm diameter, filled) connecting the exposed pad to inner-layer ground planes, θJA degrades from 50°C/W to >70°C/W; at 1A load and 25°C ambient, junction temperature may exceed 125°C - thermal vias are mandatory for full-spec operation.

Is the COMP pin internally clamped, and what are the safe voltage limits?

Yes - the COMP pin is clamped between 0.9V (min) and 2.0V (max) during normal operation, and pulled to GND in shutdown; exceeding 2.6V risks damage, so external compensation networks must limit voltage swing within this range using appropriate R/C values.

How does the EN pin behave when left floating?

When floating, the EN pin is pulled up to ~3.0V by an internal 1µA current source, enabling the device; this allows simple enable-by-default designs, but external pull-down resistors <1MΩ are required for active-low control or low-power shutdown.