Monolithic Power Systems Inc. MP8761GLE-Z

Overview

MP8761GLE-Z from Monolithic Power Systems is a fully-integrated, synchronous step-down DC/DC converter delivering 8A output current across 4.5V–18V input with 0.611V–13V adjustable output voltage, Constant-On-Time (COT) control, and integrated 28mΩ/16mΩ MOSFETs - deployed in flat-panel TV power rails and small-cell base station intermediate bus conversion.

For engineers reviewing the MP8761GLE-Z datasheet, MP8761GLE-Z pinout, MP8761GLE-Z application, or MP8761GLE-Z equivalent, key selection criteria include its 16-pin QFN-3×4mm package, non-latch OCP/OVP/thermal shutdown, programmable 200kHz–1MHz switching frequency via FREQ pin, and pre-bias start-up capability for hot-swap systems.

Technical Context

The MP8761GLE-Z implements adaptive COT control without an external oscillator, using input-voltage feed-forward through the FREQ pin to maintain stable switching frequency across input variations. Its internal 4.8V VCC LDO powers gate drivers and control logic, while external 5V bias disables the LDO to extend VIN down to 2.5V.

It operates in PWM mode under continuous conduction (CCM) and transitions to skip mode at light load, where LS-FET current modulation limits negative inductor current to −1mA, improving no-load efficiency. Protection includes valley-current OCP (8–12A), −4A to −1A negative-current limit, 117–123% VFB OVP, and thermal shutdown at 150°C with 25°C hysteresis.

Key Specifications

Pinout & Package

MP8761GLE-Z is housed in a thermally enhanced 16-pin QFN package (3mm × 4mm, 0.5mm pitch) with exposed thermal pad. Pin numbering follows JEDEC MO-220, top-view orientation, and requires PCB layout with multiple vias to PGND for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP8761GLE-Z, MP8770GQ-P offers measurable efficiency gains and digital monitoring, while TPS54821RHLR trades simplicity for design flexibility at the cost of added BOM count and slower transient response - making MP8761GLE-Z optimal for cost-sensitive, space-constrained analog POL applications needing proven COT performance.

Availability

MP8761GLE-Z is available at Aetrix Electronics and suitable for flat-panel television power supplies, small-cell base station auxiliary rails, and distributed industrial power systems requiring stable component supply with long-term lifecycle support.

Supply support for MP8761GLE-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 MP8761 belongs to MPS's high-current synchronous buck converter product line, designed specifically for compact, high-efficiency point-of-load regulation in consumer, telecom, and industrial equipment where thermal density and transient response are critical.

FAQ

What is the recommended input capacitor for MP8761GLE-Z?

Use ≥10μF X7R/X5R ceramic capacitors placed as close as possible to the IN and PGND pins. A parallel combination of 10μF + 100nF minimizes high-frequency impedance. Avoid tantalum or aluminum electrolytics due to ESR-related instability risks in COT control loops.

Can MP8761GLE-Z operate with a pre-biased output?

Yes - it features monotonic pre-bias start-up. When the FB voltage exceeds the SS capacitor voltage at power-on, both HS- and LS-FETs remain off until SS voltage rises above FB, preventing reverse current flow and ensuring safe startup into charged outputs.

How is the switching frequency set and stabilized?

Connect a resistor between FREQ and IN pins. The IC uses input-voltage feed-forward to maintain constant ON-time and thus stable f_SW across VIN variation. For example, a 453kΩ resistor sets ~600kHz at 12V_IN; equation f_SW = 10⁶/(6.1 × R_FREQ(kΩ) × V_IN(V) + 5ns) applies.

What thermal pad layout is required for reliable 8A operation?

The exposed thermal pad must be soldered to a minimum 120mm² copper pour connected via ≥6 thermal vias (0.3mm diameter) to inner-layer ground planes. Thermal resistance θ_JA drops from 46°C/W to ≤32°C/W with this layout, enabling full 8A output at +70°C ambient.

Does MP8761GLE-Z support output voltage tracking?

No - it lacks dedicated tracking pins or internal sequencing logic. Output voltage is set solely by the FB resistor divider. For tracking applications, external circuitry (e.g., DAC-controlled resistor network or dedicated tracker IC) is required.

What is the maximum allowable BST capacitor value?

Use 0.1μF ±10% X7R ceramic capacitor rated ≥16V between BST and SW. Larger values increase charge time and risk insufficient gate drive during high-duty-cycle operation; smaller values may cause HS-FET shoot-through due to inadequate bootstrap voltage hold.

How does the power-good (PG) signal behave during fault conditions?

PG goes LOW when FB falls below 80% VREF (undervoltage), exceeds 120% VREF (overvoltage), or when VCC drops below UVLO threshold. It remains LOW for ≥2.5ms after fault clearance before re-asserting HIGH, providing clean reset signaling to downstream logic.