Monolithic Power Systems Inc. MPQ2325GJ-Z

Overview

MPQ2325GJ-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter IC delivering 3A continuous output current with fixed 500kHz switching frequency, internal 90mΩ/40mΩ MOSFETs, and adjustable output voltage down to 0.8V. It operates across 4.5V–24V input range and integrates power-good indication, thermal shutdown, and over-current protection with hiccup mode - deployed in notebook I/O power rails and flat-panel display subsystems.

For engineers reviewing the MPQ2325GJ-Z datasheet, MPQ2325GJ-Z pinout, MPQ2325GJ-Z application, or MPQ2325GJ-Z equivalent, key selection criteria include its TSOT23-8 package footprint, EN/SYNC dual-function pin for enable control or external clock synchronization (200kHz–2MHz), internal soft-start (1.5ms typical), and power-save mode operation under light load.

Technical Context

The MPQ2325GJ-Z employs peak-current-mode control with internal compensation, enabling fast transient response and stable loop behavior without external compensation components. Its integrated high-side and low-side MOSFETs operate synchronously to minimize conduction losses across the full 0–3A load range.

It features a dedicated bootstrap (BST) pin driving the high-side gate via an external capacitor, a programmable feedback (FB) threshold of 791mV ±12mV, and a 40μs power-good (PG) delay with open-drain output referenced to VCC. UVLO triggers at 3.9V rising threshold with 650mV hysteresis, ensuring reliable start-up across wide input conditions.

Key Specifications

Pinout & Package

MPQ2325GJ-Z is housed in a thermally enhanced, space-constrained TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), optimized for high-power-density DC/DC conversion on compact PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2325GJ-Z, MP2325GJ-Z offers measurable improvements in output voltage accuracy and thermal resistance, while TPS54332DR trades integration for design flexibility - making MPQ2325GJ-Z optimal for space-constrained, cost-sensitive, and rapidly prototyped applications.

Availability

MPQ2325GJ-Z is available at Aetrix Electronics and suitable for notebook I/O power, digital set-top box logic supplies, and flat-panel display TCON rails requiring stable component supply, full production traceability, and long-lifecycle availability.

Supply support for MPQ2325GJ-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 emphasis on energy-efficient DC/DC conversion and motor control solutions.

The MPQ2325 belongs to MPS's MPQ-series of integrated synchronous buck converters, designed specifically for compact, high-current POL applications in consumer, computing, and industrial electronics where thermal density and layout simplicity are critical.

FAQ

What is the minimum recommended input capacitance for MPQ2325GJ-Z?

A 22μF X5R/X7R ceramic capacitor is required at the IN pin, placed directly adjacent with wide traces and multiple vias. An additional 0.1μF ceramic capacitor must be added in parallel for high-frequency decoupling. Total RMS current rating must exceed 1.5A to handle worst-case ripple at VIN = 2×VOUT.

Can MPQ2325GJ-Z operate with an output voltage lower than 0.8V?

No - the internal reference is fixed at 791mV ±12mV, and the FB pin is designed for resistive divider configurations that scale VOUT ≥ 0.8V. Attempting sub-0.8V operation violates the error amplifier's common-mode input range and results in regulation failure or instability.

How does the EN/SYNC pin behave during external clock synchronization?

When synchronized, EN/SYNC accepts 200kHz–2MHz square waves with logic-high >2V and logic-low <400mV. The internal clock aligns its rising edge to the external clock's rising edge after ~2ms lock-in. Pulse widths must remain <1.6μs (high) and <6μs (low) to prevent unintended enable/disable toggling.

Is an external bootstrap diode required for MPQ2325GJ-Z?

An external diode (e.g., 1N4148) from VCC to BST is optional and recommended only when duty cycle exceeds 65% - typically at VOUT ≥ 5V with VIN ≤ 7.5V. It improves BST capacitor charging efficiency and reduces thermal stress on the internal charge pump.

What is the maximum allowable output capacitor ESR for stable operation?

The MPQ2325GJ-Z supports output capacitors with ESR ranging from 2mΩ (ceramic) to 50mΩ (polymer/tantalum). Stability is maintained across this range due to internal Type-II compensation; however, ESR >50mΩ may degrade transient response and require external compensation.

Does MPQ2325GJ-Z support forced PWM mode?

No - it operates exclusively in automatic transition between fixed-frequency PWM (heavy load) and pulse-frequency modulation (light load, AAM mode). There is no pin or register to force continuous conduction mode; this is intentional to maximize light-load efficiency.

What PCB layout practices are critical for thermal performance?

Thermal performance depends on connecting the exposed pad (Pin 4 GND) to a minimum 100mm² inner-layer copper pour using ≥6 thermal vias (0.3mm diameter). The IN-GND and SW-GND loops must be minimized, and the BST capacitor must be placed within 2mm of Pins 3 and 5 to reduce switching node ringing.