Monolithic Power Systems Inc. MP2303DQ-LF-Z

Overview

MP2303DQ-LF-Z from Monolithic Power Systems is a monolithic synchronous buck regulator integrating high- and low-side N-channel MOSFETs, delivering 3A continuous output current across 4.75V–28V input range with fixed 340kHz switching frequency and 0.8V feedback reference. It regulates down to 0.8V output voltage and features cycle-by-cycle overcurrent protection, programmable soft-start, and thermal shutdown-used in notebook computers and distributed power systems.

For engineers reviewing the MP2303DQ-LF-Z datasheet, MP2303DQ-LF-Z pinout, MP2303DQ-LF-Z application, or MP2303DQ-LF-Z equivalent, key selection criteria include its QFN10 (3×3 mm) thermally enhanced package, integrated power switches, 125mΩ high- and low-side R_DS(ON), 1μA shutdown current, and compatibility with low-ESR ceramic output capacitors.

Technical Context

The MP2303DQ-LF-Z employs current-mode control architecture with internal transconductance error amplifier (G_EA = 550–1100 μA/V) and COMP pin-based loop compensation. Its oscillator operates at a fixed 340kHz (±20% over temperature), enabling predictable EMI filtering and stable transient response.

It integrates dual N-MOSFET power switches with matched 125mΩ R_DS(ON), uses bootstrap capacitor (SW-to-BS) for high-side gate drive, and implements UVLO (3.5–4.7V threshold), EN lockout (2.1–2.8V), and OVP (0.9–1.0V at FB) for robust system-level protection.

Key Specifications

Pinout & Package

MP2303DQ-LF-Z is housed in a 3mm × 3mm, 10-pin QFN package with exposed thermal pad on underside for enhanced heat dissipation (θ_JA = 50°C/W, θ_JC = 12°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck regulator applications.

Compared with MP2303DQ-LF-Z, MP2307DQ-LF-Z offers higher current headroom with identical footprint and control features, while TPS54302DDCR trades integration for package compatibility but sacrifices efficiency and design simplicity.

Availability

MP2303DQ-LF-Z is available at Aetrix Electronics and suitable for industrial distributed power, notebook computing, automotive infotainment, and portable medical devices requiring stable component supply, RoHS-compliant packaging, and long-lifecycle support.

Supply support for MP2303DQ-LF-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.

The MP2303 belongs to MPS's mainstream synchronous buck regulator product line, engineered for cost-sensitive, space-constrained applications demanding high integration, thermal robustness, and ease of use in consumer and industrial power supplies.

FAQ

What is the maximum recommended output voltage for MP2303DQ-LF-Z?

The MP2303DQ-LF-Z supports output voltages up to 25V, determined by the feedback divider ratio and the 0.8V reference. At higher outputs, ensure the FB divider resistors maintain ≤1% tolerance and sufficient voltage rating, and verify that the inductor saturation current and output capacitor WV rating exceed worst-case conditions.

Can MP2303DQ-LF-Z operate with an input voltage below 4.75V?

No - the absolute minimum operating input voltage is 4.75V per datasheet specifications. Below this, the UVLO circuit disables the device. Attempting operation at 4.5V or lower may result in erratic switching, failure to regulate, or undefined behavior due to insufficient gate drive and internal biasing.

Is an external bootstrap diode required for MP2303DQ-LF-Z?

An external bootstrap diode (e.g., IN4148) is optional but recommended when V_OUT/V_IN > 65% (e.g., 5V output from 7V input), as internal charge pump efficiency drops. It improves high-duty-cycle efficiency by reducing BST capacitor discharge and maintaining strong high-side gate drive.

How does the COMP pin function in MP2303DQ-LF-Z?

The COMP pin is the output of the internal transconductance error amplifier. It interfaces with an external RC network to set loop gain, phase margin, and crossover frequency (~34kHz). Proper compensation ensures stability across load, line, and temperature variations - values depend on output capacitor type (ceramic vs. aluminum) and ESR.

What thermal considerations apply to the QFN10 package?

The QFN10 package requires soldering the exposed thermal pad to a dedicated PCB copper pour connected to ≥4 thermal vias to internal ground planes. Without proper thermal relief, junction temperature can exceed 150°C at 3A load and 24V input, triggering thermal shutdown. θ_JA = 50°C/W assumes a 4-layer JEDEC-standard board.

Does MP2303DQ-LF-Z support forced PWM or power-save mode?

No - MP2303DQ-LF-Z operates exclusively in forced continuous conduction mode (CCM) at fixed 340kHz. It lacks pulse-frequency modulation (PFM) or diode emulation modes. Light-load efficiency is maintained via low quiescent current (1.5mA typical), not frequency scaling.

What is the purpose of the SS pin capacitor value calculation?

The SS pin capacitor sets soft-start duration using t_SS ≈ C_SS × 0.8V / 6μA. For example, a 100nF capacitor yields ~13.3ms ramp time. This linearly increases the internal current limit, preventing inrush into large output capacitors and avoiding input voltage sag on weak sources.