Monolithic Power Systems Inc. MP2325GJ-Z

Overview

MP2325GJ-Z from Monolithic Power Systems is a high-efficiency synchronous step-down DC/DC converter with integrated 90mΩ/40mΩ MOSFETs, delivering 3A continuous output current across a 4.5V–24V input range. It operates at a fixed 500kHz switching frequency with power-good indication, internal soft-start, and thermal shutdown-designed for compact I/O power in space-constrained notebook and display systems.

For engineers reviewing the MP2325GJ-Z datasheet, MP2325GJ-Z pinout, MP2325GJ-Z application, or MP2325GJ-Z equivalent, key selection criteria include its TSOT23-8 package footprint, 0.8V adjustable output, 791mV feedback reference, 1.5ms soft-start time, and EN/SYNC dual-function pin supporting external clock synchronization from 200kHz to 2MHz.

Technical Context

The MP2325GJ-Z uses peak-current-mode control with an internal 0.8V reference and optimized compensation network, enabling stable regulation without external loop components. Its AAM (Advanced Asynchronous Modulation) light-load mode reduces quiescent current to 130μA while maintaining output accuracy via pulse-frequency modulation.

It integrates a bootstrap regulator for high-side gate drive, with BST pin requiring an external capacitor between SW and BST. The EN/SYNC pin serves both enable logic and external clock input, with defined timing windows (≤1.6μs high pulse, ≤6μs low pulse) to avoid unintended restarts during sync operation.

Key Specifications

Pinout & Package

MP2325GJ-Z is housed in an 8-pin TSOT23 package (2.9mm × 1.6mm × 0.85mm), optimized for high-density PCB layouts with exposed thermal pad (connected to GND). Pin 4 is system ground reference; Pin 2 (IN) and Pin 3 (SW) require wide copper pours and multiple vias for thermal and current handling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RT6220AGQW and TPS54332DDAR, MP2325GJ-Z uniquely combines SYNC capability, ultra-low 130μA quiescent current, and fully integrated compensation in a TSOT23-8 package-making it optimal for compact, noise-sensitive, and battery-aware designs.

Availability

MP2325GJ-Z is available at Aetrix Electronics and suitable for notebook I/O power, digital set-top box SoC rails, flat panel monitor logic supplies, and industrial HMI power systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2325GJ-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 MP2325 belongs to MPS's high-density synchronous buck converter product line, engineered for space-constrained consumer and industrial applications demanding high efficiency, low quiescent current, and minimal external component count.

FAQ

What is the minimum recommended input capacitance for MP2325GJ-Z?

A minimum 22μF X5R/X7R ceramic capacitor is required at the IN pin, placed adjacent to the device with wide traces and multiple vias. This value ensures adequate RMS current handling (≥1.5A) and limits input ripple to <100mV under 3A load at 24V input. Larger values improve hold-up but do not reduce switching noise below the capacitor's self-resonant frequency.

Can MP2325GJ-Z operate with an output voltage lower than 0.8V?

No. The internal 0.8V reference sets the absolute lower limit for regulated output voltage. The FB pin compares the resistor-divider output against this reference; attempting sub-0.8V regulation violates the error amplifier's operating range and causes instability or unregulated behavior. Output voltages from 0.8V to VIN×0.95 are supported.

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

When an external clock (200kHz–2MHz) is applied to EN/SYNC, the internal oscillator locks to its rising edge with ≤2ms settling time. The pin must meet strict timing: high pulses <1.6μs and low pulses <6μs. Exceeding either causes unintended shutdown or mis-synchronization due to internal state machine timeout.

What is the purpose of the BST capacitor, and what value is recommended?

The BST capacitor (0.1μF–1μF, X7R ceramic) forms a floating supply for the high-side MOSFET gate driver. It charges through the internal bootstrap diode when SW is low and powers the HS driver when SW is high. A 0.22μF capacitor is typical; larger values improve gate drive strength at high duty cycles but increase start-up time.

Does MP2325GJ-Z support forced PWM mode, or is it limited to AAM?

MP2325GJ-Z operates exclusively in AAM (Advanced Asynchronous Modulation) at light loads and fixed-frequency peak-current mode at heavy loads. There is no pin or register to force continuous PWM; the transition occurs automatically at ~100mA load based on internal COMP voltage comparison with VAAM threshold.

What failure modes trigger hiccup-mode operation?

Hiccup mode activates only when over-current protection persists long enough to cause FB voltage to drop below 50% of VREF (i.e., <395mV), indicating sustained short-circuit or severe overload. The device then cycles ON for ~10ms, OFF for ~100ms until fault clears-limiting average power dissipation to <1W and preventing thermal damage.

Is the TSOT23-8 package thermally enhanced, and how should the thermal pad be handled?

Yes-the TSOT23-8 package includes an exposed thermal pad (pin 4 GND) that must be soldered to a dedicated PCB copper pour tied to system ground. At least four 0.3mm vias connecting the pad to inner-layer ground planes are required to achieve θJA ≈ 100°C/W. Leaving the pad unconnected degrades thermal performance by >40°C at 3A load.