Monolithic Power Systems Inc. MP8770CGQ-Z

Overview

MP8770CGQ-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter IC delivering 8A continuous output current with 3V–17V input range, fixed 700kHz switching frequency, and forced PWM operation in CCM mode. It integrates 22mΩ/10mΩ high-side/low-side MOSFETs, supports adjustable output down to 0.6V, and features power-good signaling, thermal shutdown, and hiccup-mode over-current protection - deployed in security cameras and flat-panel displays.

For engineers reviewing the MP8770CGQ-Z datasheet, MP8770CGQ-Z pinout, MP8770CGQ-Z application, or MP8770CGQ-Z equivalent, key selection criteria include its COT control architecture for fast transient response, QFN-16 (3mm×3mm) thermal performance (θJA = 38°C/W), pre-biased start-up capability, and integrated VCC LDO with 3.4V output - all critical for compact, high-efficiency 1V–5V point-of-load designs.

Technical Context

The MP8770CGQ-Z employs constant-on-time (COT) control with internal ramp compensation to maintain stable regulation across wide VIN and load variations while enabling ceramic-output-capacitor compatibility without external compensation. Its valley-current-limit OCP mechanism triggers hiccup mode upon sustained overload, ensuring self-recovery without latch-up.

It integrates a 3.4V internal VCC LDO powered from VIN, a bootstrap circuit with dedicated BST pin and 1.7V UVLO, and dual-level PG monitoring (90%/80% VREF thresholds with 50μs delay). EN pin includes 1.2MΩ internal pull-down, supporting direct VIN connection and seamless power sequencing.

Key Specifications

Pinout & Package

MP8770CGQ-Z is housed in a thermally enhanced QFN-16 package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad (PGND-connected) for efficient heat dissipation. The package supports reflow soldering per JEDEC J-STD-020 and achieves θ_JA = 38°C/W on a 4-layer EVB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP8772GQ-Z and RT7295BGSP, the MP8770CGQ-Z uniquely combines 8A capability in a minimal 3mm×3mm QFN with COT control, integrated VCC, and robust power sequencing - making it optimal for space-constrained, high-transient industrial and consumer PoL applications where reliability and ease of design are prioritized over raw current headroom or legacy package compatibility.

Availability

MP8770CGQ-Z is available at Aetrix Electronics and suitable for security cameras, digital set-top boxes, and flat-panel display TCON modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP8770CGQ-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, founded in 1997 and headquartered in Kirkland, Washington.

The MP8770C product line delivers highly integrated, high-current DC/DC converters optimized for compact, high-efficiency point-of-load regulation in imaging, networking, and consumer electronics - emphasizing ease of design, thermal robustness, and feature-rich power sequencing.

FAQ

What is the minimum recommended soft-start capacitor value for MP8770CGQ-Z?

The datasheet specifies a minimum soft-start capacitor of 4.7nF to ensure reliable charging and prevent premature exit from soft-start. Using smaller values risks violating the internal timing window, potentially causing output overshoot or failure to regulate. For a typical 1ms ramp time, a 10nF capacitor is commonly selected with the internal 6µA current source.

Can MP8770CGQ-Z operate with an input voltage below 3V?

No - the absolute minimum operating input voltage is 3V per the Recommended Operating Conditions table. Below this, the internal VCC LDO cannot sustain regulation, and the control circuitry fails to initialize. The absolute maximum rating of −0.3V does not imply functional operation; operation below 3V is undefined and may result in erratic behavior or no regulation.

How does the power-good (PG) pin behave during thermal shutdown?

During thermal shutdown, the PG pin is pulled low immediately - independent of FB voltage - as part of the fault-signaling protocol. This provides unambiguous system-level indication of thermal violation. Recovery occurs only after junction temperature falls below the hysteresis threshold (~130°C), at which point PG returns high after the standard 50µs delay once V_FB stabilizes above 90% of V_REF.

Is the MP8770CGQ-Z compatible with ceramic output capacitors only?

Yes - the internal COT compensation is specifically designed for stability with low-ESR ceramic output capacitors (e.g., X5R/X7R 22µF ×4 parallel). Unlike voltage-mode controllers, it does not require added ESR or external Type-II/III compensation networks, simplifying design and improving transient response.

What is the purpose of the AGND pin, and how should it be routed?

AGND serves as the dedicated analog reference for the feedback amplifier, soft-start comparator, and internal reference circuits. It must be isolated from noisy PGND currents and connected directly to the PGND plane only at a single point near the IC's thermal pad - typically via a short trace or small copper bridge - to prevent ground bounce from corrupting regulation accuracy.

Does MP8770CGQ-Z support output voltages above 5V?

The datasheet specifies a maximum output voltage of 12V (VIN × D_MAX), but practical use above 5V is limited by the 17V absolute maximum input rating and duty-cycle constraints. At VIN = 17V, the theoretical max V_OUT is ~12V, but efficiency and thermal performance degrade significantly above 5V due to reduced duty cycle and increased switching losses.

How is the valley-current limit of 8A enforced in MP8770CGQ-Z?

The valley-current limit is sensed across the low-side MOSFET's R_DS(ON) during its conduction phase. When the instantaneous current reaches 8A (typical), the controller terminates the current cycle and initiates hiccup mode after V_FB drops below 50% of V_REF. This is a cycle-by-cycle, non-latching protection verified across temperature and process corners.