Monolithic Power Systems Inc. MP2238GD-Z

Overview

MP2238GD-Z from Monolithic Power Systems is a high-efficiency, synchronous step-down DC/DC converter delivering 8A continuous output current with 4.2V–18V input range, 600kHz switching frequency, and constant-on-time (COT) control for fast transient response. It integrates 22mΩ/10mΩ high- and low-side MOSFETs in a thermally enhanced 12-pin QFN 2mm×3mm package, targeting compact power rails in flat-panel displays and digital TV power supplies.

For engineers reviewing the MP2238GD-Z datasheet, MP2238GD-Z pinout, MP2238GD-Z application, or MP2238GD-Z equivalent, key selection criteria include its hiccup-mode over-current protection, adjustable 0.6V reference voltage, thermal shutdown at 150°C, and bootstrap capacitor requirement for high-side gate drive-critical for stable 1V–12V output designs under dynamic load conditions.

Technical Context

The MP2238GD-Z employs constant-on-time (COT) control with internal ramp compensation to ensure loop stability without requiring output capacitor ESR, enabling full ceramic capacitor solutions. Its valley-current sensing algorithm monitors low-side MOSFET R_DS(ON) to enforce 8A cycle-by-cycle current limiting and initiate hiccup-mode recovery upon sustained over-current or short-circuit events.

It features integrated bootstrap charging with internal UVLO (1.2V rising threshold, 150mV hysteresis) on the BST pin, Ton extension for low-dropout operation down to 260kHz minimum frequency, and separate AGND and PGND pins to isolate analog reference paths from high-current switching return paths.

Key Specifications

Pinout & Package

MP2238GD-Z is housed in a thermally optimized 12-pin QFN package (2mm × 3mm, 0.5mm pitch) with exposed thermal pad. The package supports high-power density layouts and requires PCB copper area and vias under the pad for effective heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2238GD-Z, MP2315GJ-Z trades peak current and dropout capability for lower cost and smaller footprint, while RT7290BZSP offers alternative control architecture at the expense of added external components and reduced transient immunity-making MP2238GD-Z optimal for high-dynamic-load, space-constrained, and thermally demanding applications.

Availability

MP2238GD-Z is available at Aetrix Electronics and suitable for flat-panel television power supplies, digital set-top box main rails, and industrial embedded core voltage generation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2238GD-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 power management ICs, with design focus on integration, efficiency, and thermal optimization for consumer, computing, and industrial markets.

The MP2238 belongs to MPS's high-current synchronous buck converter product line, engineered specifically for compact, high-efficiency point-of-load regulation in display, broadcast, and embedded systems where board space and thermal performance are critical constraints.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP2238GD-Z does not require output capacitor ESR for stability due to internal ramp compensation. For 1V/8A operation, use ≥100µF total ceramic capacitance (e.g., four 22µF X7R 0805s) with ≤5mΩ ESL to limit output ripple to <20mV_pp. Lower capacitance may cause instability under heavy transient loads.

Can MP2238GD-Z operate with an input voltage below 4.2V?

No-absolute minimum input is 4.2V per datasheet specifications. Below this, UVLO prevents startup and internal bias circuits fail to regulate. Attempting operation at 4.0V causes erratic switching, output collapse, and potential damage due to insufficient gate drive voltage for the high-side MOSFET.

How is the hiccup-mode timeout determined during over-current events?

Hiccup entry depends on concurrent over-current and under-voltage detection: if valley current exceeds 9.5A *and* output drops below 80% of target (UV1), the device waits 30 cycles before entering hiccup; if output falls below 60% (UV2), it enters hiccup after only 3 cycles-enabling faster protection during hard shorts.

Is an external bootstrap diode required for reliable operation?

An external BST diode (e.g., 1N4148) is optional but recommended when VIN < 5V and duty cycle >65% (e.g., 5V→3.3V), as internal bootstrap charging becomes marginal. Without it, high-side gate drive collapses, causing excessive conduction loss and thermal stress on the LS-FET.

What is the maximum allowable PCB trace length between BST and SW pins?

The BST-to-SW trace must be ≤2mm in length and ≥0.3mm wide, with no vias or stubs. Longer traces increase parasitic inductance, causing BST voltage droop during switching transitions and risking high-side MOSFET shoot-through or premature turn-off.

Does MP2238GD-Z support pre-bias start-up?

Yes-when the output is pre-biased, the MP2238GD-Z disables both HS- and LS-FET switching until the internal soft-start voltage exceeds the FB voltage. This prevents reverse current flow and avoids output voltage collapse or inductor saturation during hot-plug scenarios.

How does thermal performance change with different PCB layer counts?

On a 4-layer board (EV2238-D-00A), θ_JA is 34°C/W; on 2-layer boards, θ_JA rises to ~65°C/W. At 8A load and 25°C ambient, junction temperature increases from ~110°C (4-layer) to ~195°C (2-layer)-exceeding 150°C shutdown threshold and requiring derating to ≤4.5A.