Monolithic Power Systems Inc. MP2308GD-P

Overview

MP2308GD-P from Monolithic Power Systems is a synchronous step-down DC-DC converter IC with integrated 60 mΩ high-side and 30 mΩ low-side MOSFETs, delivering up to 4A continuous output current across a 4.75V–18V input range, operating at 300kHz–2MHz programmable switching frequency, and featuring EN control, external soft-start, and thermal shutdown - deployed in DSL modems for stable 3.3V rail generation.

For engineers reviewing the MP2308GD-P datasheet, MP2308GD-P pinout, MP2308GD-P application, or MP2308GD-P equivalent, key selection criteria include input voltage range compatibility, internal R_DS(on) values, programmable frequency tuning via FREQ pin resistor, light-load mode configurability via AAM pin, and QFN2x3 thermal performance under 4A load.

Technical Context

The MP2308GD-P uses peak-current-mode control with fixed-frequency PWM, where an internal oscillator initiates each cycle and the high-side switch turns off when sensed inductor current reaches the COMP voltage threshold set by the error amplifier. The internal 0.815V feedback reference enables precise output regulation across temperature.

Its integrated 5V VCC regulator powers internal circuitry across full VIN range; bootstrap charging (BST–SW) sustains high-side gate drive; and hiccup-mode overcurrent protection activates when FB drops below 70% of reference while current limit is exceeded - ensuring fault resilience without latch-up.

Key Specifications

Pinout & Package

MP2308GD-P is housed in a thermally enhanced 2mm × 3mm, 14-pin QFN package with exposed thermal pad (connected to GND), supporting high-power density designs and requiring multi-via GND connections for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2307DN-LF-P, MP2308GD-P adds 1A current headroom, AAM-configurable light-load modes, and frequency programming - critical for compact, adaptive power in broadband equipment. Versus TPS54332DR, it trades external component count and design flexibility for faster time-to-market and smaller PCB area.

Availability

MP2308GD-P is available at Aetrix Electronics and suitable for DSL modems, cable modems, set-top boxes, and industrial IoT gateways requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP2308GD-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2308 belongs to MPS's mainstream synchronous buck converter product line, engineered for space-constrained broadband and consumer electronics applications demanding high integration, efficiency, and reliability at 4A output levels.

FAQ

What is the minimum recommended input capacitance for MP2308GD-P at 4A output?

A minimum 22µF X5R/X7R ceramic capacitor is required at the IN pin, placed within 2mm of pins 3 (IN) and GND. For high-RMS applications (e.g., 12V_IN/3.3V_OUT), use ≥47µF with 2× parallel 0.1µF ceramics near the IC to suppress high-frequency noise and ensure stable switching.

How does the AAM pin affect efficiency and output ripple?

When AAM is tied to VCC, MP2308GD-P enters Pulse Skip Mode (PSM), reducing switching losses below 100mA load and improving light-load efficiency by up to 15%. However, this increases output voltage ripple due to burst-mode operation; grounding AAM forces CCM for consistent ripple <20mV but lowers efficiency at light loads.

Can MP2308GD-P safely start into a pre-biased output?

Yes - MP2308GD-P features pre-bias start-up protection. If the FB voltage exceeds the soft-start capacitor voltage at power-on, the IC disables both HS and LS switches until the SS capacitor charges above the sensed output voltage, preventing reverse current flow and output collapse.

What is the maximum allowable BST capacitor value and type?

The BST capacitor must be 0.1–1µF ceramic (X5R/X7R), rated ≥10V. Larger values (>1µF) risk excessive inrush current into the bootstrap circuit during startup, potentially causing gate driver instability; tantalum or electrolytic types are prohibited due to ESR-induced timing errors and reliability concerns.

Does MP2308GD-P support output voltages below 0.815V?

No - the internal reference is fixed at 0.815V, and the FB pin is designed for resistive divider configurations that scale higher output voltages (e.g., 1.05V–5V). For sub-0.8V outputs, an external reference or different converter architecture (e.g., current-mode with adjustable reference) is required.

How is thermal performance affected by PCB layout of the exposed pad?

The exposed thermal pad must be soldered to a solid GND plane with ≥4 thermal vias (0.3mm diameter, filled or capped). Without this, θ_JA degrades from 70°C/W to >120°C/W, causing premature thermal shutdown at ≤2.5A load - verified per JESD51-7 4-layer board test conditions.

Is an external bootstrap diode necessary for all applications?

An external Schottky diode (e.g., IN4148) from VCC to BST is recommended only when duty cycle >65% (e.g., 5V_OUT from 7V_IN) to improve bootstrap capacitor recharge efficiency and prevent BST undervoltage shutdown; it is optional for 3.3V/12V or 5V/15V configurations.