Monolithic Power Systems Inc. MP8720GQ-Z

Overview

MP8720GQ-Z from Monolithic Power Systems is a synchronous buck converter IC designed for high-density DC/DC power conversion in DDR memory and USB Type-C applications. It delivers 10A continuous output current, supports 4.5V–26V input range, features adjustable current limit (8.5A–16.5A), operates at fixed 700kHz switching frequency, and integrates internal high- and low-side MOSFETs with 19mΩ/7mΩ R_DS(ON).

For engineers reviewing the MP8720GQ-Z datasheet, MP8720GQ-Z pinout, MP8720GQ-Z application, or MP8720GQ-Z equivalent, this device is selected for fast transient response in compact power rails requiring adaptive COT control, DC auto-tune loop stability, ceramic-capacitor compatibility, and programmable over-current protection via CLM resistor selection.

Technical Context

The MP8720GQ-Z implements adaptive constant-on-time (COT) control with internal ramp compensation to ensure stability with low-ESR ceramic output capacitors-eliminating need for external ramp circuitry. Its valley-current sensing OCL uses the low-side FET's R_DS(ON) as the current-sense element, enabling cycle-by-cycle protection without external sense resistors.

DC auto-tune loop dynamically adjusts loop gain across line and load conditions to maintain tight regulation; the integrated soft-start (2.2ms typical) and open-drain power-good (PG) output with 95%/90% V_REF thresholds provide precise sequencing and fault signaling. MODE pin selects between DCM/CCM and output voltage ranges (<3V or ≥3V), supporting flexible system-level power architecture.

Key Specifications

Pinout & Package

MP8720GQ-Z is housed in a thermally enhanced QFN-16 (3mm × 3mm) package with exposed thermal pad, optimized for high-power density PCB layouts and efficient heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP8720GQ-Z, MPQ8720GQ-Z adds automotive qualification without altering functionality, while RTQ2132BGQW-Z trades analog configurability for digital telemetry and fixed output-making MP8720GQ-Z optimal for cost-sensitive, high-flexibility industrial and consumer power rails.

Availability

MP8720GQ-Z is available at Aetrix Electronics and suitable for DDR memory power supplies, USB Type-C sink implementations, and networking system point-of-load converters requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP8720GQ-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, and global manufacturing partnerships.

The MP8720 belongs to MPS's high-density synchronous buck converter product line, engineered specifically for space-constrained, high-current applications such as DDR memory, USB-C PD, and distributed power architectures where efficiency, transient response, and integration are critical.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP8720GQ-Z is stable with ceramic output capacitors as low as 22µF per phase (e.g., 3×22µF = 66µF total). Stability is ensured by internal ramp compensation-no ESR requirement. For 5V/10A operation, 5×22µF ceramic (110µF total) is typical, reducing output ripple to <20mV_pp under full load transient.

How does the CLM pin affect over-current protection behavior?

The CLM pin sets the valley current limit threshold via resistor value: 0Ω = 8.5A, 90kΩ = 10A, 150kΩ = 13A, floating = 16.5A. This directly determines the inductor valley current at which cycle-by-cycle OCL triggers-enabling precise matching to application fault thresholds without changing external components.

Can the MP8720GQ-Z operate with an input voltage below 4.5V?

No. The absolute minimum input voltage is 4.5V per the VIN UVLO threshold (4.2V rising with 360mV hysteresis). Operation below 4.5V violates recommended conditions and may cause erratic startup, poor regulation, or failure to enable-even if VIN momentarily exceeds 4.2V during ramp-up.

Is external bootstrap capacitor mandatory, and what value is recommended?

Yes-an external bootstrap capacitor between BST and SW is mandatory for high-side gate drive. A 0.1µF X7R ceramic capacitor placed within 2mm of pins 9 (SW) and 10 (BST) is recommended. Larger values (e.g., 0.22µF) improve reliability under high-duty-cycle conditions but are not required for nominal operation.

Does the MP8720GQ-Z support pre-biased output startup?

Yes. When EN rises while V_OUT is pre-biased above the target voltage, the MP8720GQ-Z disables both HS- and LS-FETs until the internal reference voltage ramps above the sensed FB voltage-preventing reverse current flow and ensuring monotonic start-up without output voltage overshoot.

What thermal derating applies above 85°C ambient?

With θ_JA = 55°C/W on a 4-layer PCB, maximum continuous power dissipation drops linearly: at 85°C ambient, PD_MAX = (150°C − 85°C)/55°C/W = 1.18W. At 10A/5V output, this corresponds to ~23% duty cycle-requiring thermal relief (copper pour, airflow, or reduced load) above 85°C ambient for sustained operation.

How is power-good (PG) timing affected by soft-start duration?

PG asserts high after V_FB reaches 95% of V_REF, which occurs near the end of the 2.2ms soft-start ramp. Typical PG delay from EN rising is 2.3–2.5ms-ensuring reliable sequencing before downstream logic releases reset. PG deasserts within 1µs of EN going low.