Monolithic Power Systems Inc. MP4568GQ-Z

Overview

MP4568GQ-Z from Monolithic Power Systems is a 60V, 100mA synchronous step-down DC/DC converter with integrated high-side (2.25Ω R_DS(on)) and low-side (0.7Ω R_DS(on)) MOSFETs, 1.0V feedback reference, programmable peak current limit (55–260mA), and 4.5V–45V input range. It delivers >90% efficiency at 10V_IN/5V_OUT/2mA in automotive and industrial power systems.

For engineers reviewing the MP4568GQ-Z datasheet, MP4568GQ-Z pinout, MP4568GQ-Z application, or MP4568GQ-Z equivalent, key selection criteria include its 5μA shutdown current, bootstrap-driven high-side gate drive, precision current-limiting without sense resistor, thermal shutdown at 160°C, and compatibility with ceramic output capacitors in space-constrained 3mm×3mm QFN10 layouts.

Technical Context

The MP4568GQ-Z employs constant-on-time (COT)-derived PWM control with zero-current detection (ZCD) for cycle-by-cycle current limiting and light-load frequency scaling. Its internal 1V reference compares against FB voltage to regulate output, while ILIM sets peak inductor current via external resistor without sensing loss.

Bootstrap charging is managed by an internal regulator that drives BST from VIN when SW is low, requiring ≥2.4V BST–SW differential for high-side driver enablement. BIAS pin supports optional external bias supply (>2.9V) to improve efficiency and power LS driver above 4.5V.

Key Specifications

Pinout & Package

The MP4568GQ-Z is housed in a thermally enhanced 3mm×3mm QFN10 package with exposed thermal pad (pin 3 GND). Pin 1 (BST) requires a 0.1μF ceramic capacitor to SW; pin 4 (BIAS) accepts external bias supply to improve efficiency; pin 7 (SS) controls soft-start ramp time via external capacitor.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4568GQ-Z, the original MP4568GQ-Z lacks AEC-Q100 qualification but offers identical performance at lower cost for industrial use; versus LMR14010ADRCR, it trades output current headroom for smaller footprint, lower IQ, and integrated FETs-ideal for space- and power-constrained 100mA applications.

Availability

MP4568GQ-Z is available at Aetrix Electronics and suitable for 4–20mA current loop transmitters, automotive body control modules, and battery-powered IoT sensor nodes requiring stable component supply across design-in, prototyping, and volume production phases.

Supply support for MP4568GQ-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 distribution through authorized partners.

The MP4568 belongs to MPS's high-voltage synchronous buck converter product line, engineered specifically for robust, compact DC/DC conversion in automotive, industrial, and instrumentation applications where input transients, low quiescent current, and thermal reliability are critical.

FAQ

What is the minimum input voltage required for MP4568GQ-Z to start switching?

The MP4568GQ-Z begins operation when VIN exceeds the UVLO rising threshold of 4.0V (typical 4.2V). Below this, the controller remains disabled regardless of EN state. Startup also requires BST–SW voltage ≥2.4V for high-side driver enablement, which depends on sufficient VIN–VOUT headroom during bootstrap charging.

Can MP4568GQ-Z operate with an output voltage lower than 1.0V?

No. The internal feedback reference is fixed at 1.0V, and the FB pin compares the resistive divider output against this reference. Output voltages below 1.0V cannot be regulated because the error amplifier lacks a lower reference target. Minimum practical output is 1.0V, set by connecting FB directly to VOUT.

How does the ILIM pin affect maximum output current?

ILIM sets peak inductor current (I_PEAK = 55–260mA). Since maximum continuous output current equals half the peak current in continuous conduction mode, the highest achievable I_OUT is 130mA (at I_PEAK = 260mA), though rated output is specified at 100mA for thermal and reliability margins across temperature.

Is an external feedforward capacitor required between VOUT and FB?

A 39pF feedforward capacitor is recommended to suppress switching frequency jitter caused by FB pin sensitivity to output ripple. Without it, small VOUT ripple can modulate the PWM comparator threshold, causing variable on-time and increased conducted EMI-especially noticeable at light loads with low output ripple.

What is the role of the BIAS pin, and when should it be used?

The BIAS pin supplies power to the internal 2.6V regulator and LS gate driver. When connected to a stable 2.9–5.5V source (e.g., regulated VOUT), it improves conversion efficiency by reducing VIN supply current and enabling full LS driver strength. Use BIAS whenever the output voltage falls within this range; otherwise, connect to an external bias rail ≥4.5V.

Does MP4568GQ-Z support forced PWM mode?

No. The MP4568GQ-Z operates in automatic PFM/PWM hybrid mode only. It scales switching frequency downward under light load to maintain high efficiency but does not offer a pin-selectable forced PWM mode. This eliminates beat-frequency noise but means frequency varies with load and input voltage.

How is thermal performance affected by PCB layout?

Thermal resistance θ_JA is 50°C/W on a standard 4-layer JEDEC board. To achieve rated 100mA output at +85°C ambient, the exposed GND pad must be soldered to ≥200mm² of 2oz copper with ≥4 thermal vias. Poor layout increases junction temperature, triggering thermal shutdown at lower loads.