Monolithic Power Systems Inc. MP2326GD-Z

Overview

MP2326GD-Z from Monolithic Power Systems is a fully integrated, synchronous step-down DC-DC converter with constant-on-time (COT) control, delivering 4A continuous output current across a 3.9V–19V input range, featuring 40µA quiescent current, 0.6V adjustable output, and integrated 90mΩ/30mΩ high-side/low-side MOSFETs. It targets battery-powered portable electronics requiring ultra-low standby power and fast transient response.

For engineers reviewing the MP2326GD-Z datasheet, MP2326GD-Z pinout, MP2326GD-Z application, or MP2326GD-Z equivalent, key selection criteria include light-load efficiency in auto PFM/PWM mode, programmable soft-start timing, power-good signaling with 140µs delay, and thermal shutdown with 20°C hysteresis for robust system-level power management.

Technical Context

The MP2326GD-Z implements COT control with feed-forward input voltage compensation to maintain stable switching frequency across input variations while enabling sub-100ns minimum on-time (90ns typ.) and 150ns minimum off-time for wide VIN/VOUT ratios. Its internal 5V LDO powers the bias circuitry and requires local 1µF decoupling at VCC.

It supports dual operating modes via FREQ/MODE pin configuration: forced PWM (for fixed-frequency CCM operation) or auto PFM/PWM (for adaptive frequency reduction at light loads), with programmable soft-start current (4–11µA) and external ramp compensation (CR pin) to stabilize ceramic-capacitor-based outputs.

Key Specifications

Pinout & Package

MP2326GD-Z is housed in a thermally enhanced 2mm × 3mm, 14-pin QFN package with exposed thermal pad (EP) for efficient heat dissipation. The package supports reflow soldering per JEDEC J-STD-020 and requires controlled PCB layout with multiple vias under EP to GND plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RT6220AGQW and TPS543320RHLR, MP2326GD-Z delivers superior light-load efficiency due to its 40µA IQ and adaptive PFM/PWM mode, occupies 35% less PCB area than the TPS543320, and offers direct frequency and mode configurability without external clock sources or digital interfaces.

Availability

MP2326GD-Z is available at Aetrix Electronics and suitable for tablet PCs, solid state drives, and battery-operated medical sensors requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2326GD-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP2326 belongs to MPS's high-efficiency, low-IQ DC-DC converter product line, designed specifically for portable and battery-powered systems where extended runtime, small solution size, and robust transient performance are critical.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP2326GD-Z requires ≥22µF ceramic output capacitance with low ESR for stable operation in PWM mode. For pre-biased start-up or high-reliability applications, use ≥47µF with X5R/X7R dielectric and ensure total effective capacitance remains ≥22µF after DC bias derating.

Can the MP2326GD-Z operate with an input voltage below 3.9V?

No. The absolute minimum input voltage is 3.9V per datasheet specifications. Below this threshold, the under-voltage lockout (UVLO) prevents startup, and operation is not guaranteed. Attempting to operate below 3.5V may cause erratic behavior or failure to regulate.

How is the soft-start time calculated for a given capacitor value?

Soft-start time (ms) = (C_SS × 0.6V) / 8µA, where C_SS is in nF and 0.6V is the internal reference. For example, a 10nF capacitor yields ~0.75ms ramp time. Minimum recommended C_SS is 4.7nF for outputs >330µF to avoid current-limit tripping.

Does the PG pin require an external pull-up resistor?

Yes. PG is an open-drain output and must be pulled up externally-typically with a 100kΩ resistor-to VCC or another valid logic-high rail. Without pull-up, PG cannot assert high and will remain floating or low, preventing proper power sequencing.

What is the maximum achievable switching frequency with VIN = 12V and VOUT = 1.2V?

With VIN = 12V and VOUT = 1.2V, the maximum switching frequency is limited by minimum on-time (90ns) and minimum off-time (150ns). Using Equation (4) and (5), the practical maximum is ~1.1MHz. Exceeding this causes duty-cycle violation and loss of regulation.

Is the CR pin mandatory for all applications?

No. CR is required only when using low-ESR ceramic output capacitors (e.g., X5R/X7R) in PWM mode to stabilize the control loop. With higher-ESR electrolytic or polymer capacitors, external ramp compensation is unnecessary. Typical Cr values range from 56pF to 150pF depending on VOUT and frequency.

How does the MP2326GD-Z handle pre-biased outputs during startup?

The MP2326GD-Z supports monotonic pre-bias start-up: when EN rises, it refreshes the BST capacitor and charges the SS node. If BST voltage exceeds 2.2V and SS voltage exceeds the sensed FB voltage, regulation begins without reverse current flow or output voltage collapse.