Monolithic Power Systems Inc. MP8770GQ-Z

Overview

MP8770GQ-Z from Monolithic Power Systems is a fully integrated, synchronous step-down DC/DC converter with internal 22mΩ/10mΩ MOSFETs, delivering up to 8A continuous output current across a 3V–17V input range. It employs constant-on-time (COT) control for fast transient response and tight regulation, operates at a fixed 700kHz switching frequency, and integrates EN, PG, soft-start, and comprehensive protection (OCP, SCP, UVP, thermal shutdown). It powers core rails in compact security cameras and digital set-top boxes.

For engineers reviewing the MP8770GQ-Z datasheet, MP8770GQ-Z pinout, MP8770GQ-Z application, or MP8770GQ-Z equivalent, key selection considerations include its QFN-16 (3mm×3mm) package thermal performance (θJA = 38°C/W), COT-based light-load efficiency in PFM mode, pre-biased start-up capability, and power-good timing behavior with 50µs delay and 90%/80% VFB thresholds.

Technical Context

The MP8770GQ-Z implements a constant-on-time (COT) control architecture with internal ramp compensation, enabling stable operation with ceramic output capacitors and eliminating external loop compensation. Its valley-current-limit OCP mechanism triggers hiccup-mode recovery upon sustained overload, while the integrated 3.4V VCC LDO supplies internal circuitry across the full 3V–17V VIN range.

It features dual ground domains-AGND for signal reference and PGND for high-current return-with strict PCB layout separation required. Bootstrap charging is managed via an internal regulator with BST UVLO (1.7V rising threshold) and a recommended <4.7Ω BST resistor to sustain high-side gate drive during continuous conduction mode.

Key Specifications

Pinout & Package

MP8770GQ-Z is housed in a thermally enhanced QFN-16 package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad (Pin 9–13 PGND) for direct PCB copper connection. The package supports ≤3.2W continuous power dissipation at +25°C ambient on a 4-layer EV8770-Q-00A board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2451DT-LF-Z and TPS54821RHLR, the MP8770GQ-Z uniquely delivers 8A integration, COT-based simplicity, and production-ready power sequencing (EN/PG) in a 3mm×3mm footprint-making it optimal for cost- and space-constrained consumer electronics requiring robust, self-contained regulation.

Availability

MP8770GQ-Z is available at Aetrix Electronics and suitable for security cameras, digital set-top boxes, and flat-panel display power subsystems requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for MP8770GQ-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 global design centers and ISO 9001-certified operations.

The MP8770 belongs to MPS's high-current monolithic buck converter product line, engineered specifically for compact, high-efficiency power delivery in consumer and industrial edge devices where thermal density and layout simplicity are critical constraints.

FAQ

What is the minimum recommended soft-start capacitor value for MP8770GQ-Z?

The datasheet specifies avoiding SS capacitors less than 4.7nF to prevent premature current limiting during startup. A 10nF capacitor yields ~14ms soft-start time (t_SS = 0.83·C_SS/0.6V), balancing inrush control and system boot speed for typical 1.2V/3.3V rails with ≤1000µF output capacitance.

Does MP8770GQ-Z support forced PWM mode, or does it automatically enter PFM at light load?

The MP8770GQ-Z automatically enters pulse-frequency modulation (PFM) mode under light load to maintain high efficiency; it does not support forced PWM. In PFM, the LS-FET driver goes Hi-Z when inductor current reaches zero, reducing switching losses and achieving <30µA total input current at no load with 12V_IN/1.2V_OUT.

How is thermal performance affected by the QFN-16 exposed pad connection?

Thermal resistance θ_JA drops from 50°C/W (JEDEC board) to 38°C/W (EV8770-Q-00A 4-layer board) when the exposed PGND pad is soldered to ≥2 cm² of inner-layer copper with ≥6 thermal vias. Omitting this connection degrades junction temperature rise by >25°C at 6A load, risking thermal shutdown.

Can MP8770GQ-Z be used with an input voltage below 3V?

No. The absolute minimum operating input voltage is 3V per the Recommended Operating Conditions table. Below 3V, the internal VCC LDO cannot regulate, EN UVLO fails to release, and the high-side gate driver lacks sufficient bootstrap voltage-causing immediate functional failure or erratic switching.

What happens to the PG pin during thermal shutdown?

During thermal shutdown, the PG pin is actively pulled low within microseconds, independent of V_FB level. This provides immediate system-level fault indication, allowing host controllers to log thermal events or initiate graceful shutdown before junction temperature exceeds 150°C.

Is the MP8770GQ-Z pin-compatible with earlier MP8770 variants like MP8770GQ?

Yes. MP8770GQ-Z is the tape-and-reel packaging variant of MP8770GQ; both share identical die, pinout, electrical characteristics, and thermal profile. The "-Z" suffix denotes reel packaging only and introduces no functional or mechanical differences.