Monolithic Power Systems Inc. MP5418GQG-Z

Overview

MP5418GQG-Z from Monolithic Power Systems is a monolithic negative charge pump IC with integrated adjustable negative linear regulator, delivering dual outputs: unregulated −1×VIN (VOUT1) and regulated VOUT2 = −1×CTL voltage (0 V to −VIN). It operates from 2.3 V to 5 V input, supports up to 200 mA total output current, achieves 220 μA quiescent current, and uses only four 4.7 μF ceramic capacitors. It is deployed in optical modules for biasing APDs and TEC drivers.

For engineers reviewing the MP5418GQG-Z datasheet, MP5418GQG-Z pinout, MP5418GQG-Z application, or MP5418GQG-Z equivalent, key selection criteria include its dual-output architecture (charge pump + adjustable negative LDO), ultra-low IQ, soft-start slew rate (5 V/ms), dropout voltage (20–90 mV at 60 mA), and QFN-10 (1.4 mm × 1.8 mm) package thermal performance (θJA = 85 °C/W).

Technical Context

The MP5418 integrates a switched-capacitor charge pump with auto-adjusting oscillator frequency (30–550 kHz) that scales with load and VIN–VOUT1 gap to minimize ripple under heavy load. Its negative linear regulator uses internal feedback to precisely track −1×CTL voltage, enabling direct DAC interfacing without external resistors.

It features dual protection: foldback current limiting (1 A peak charge pump current) and thermal shutdown (160 °C with 30 °C hysteresis), plus EN-controlled power sequencing with 135–285 μs turn-on delay and automatic output discharge (RDIS1 = 170–310 Ω, RDIS2 = 80–146 Ω) during disable.

Key Specifications

Pinout & Package

MP5418GQG-Z is housed in an ultra-low-profile QFN-10 package (1.4 mm × 1.8 mm, 0.5 mm pitch) with exposed thermal pad for enhanced thermal dissipation (θJC = 45 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative charge pump + adjustable regulator applications.

Compared with MAX1759EUA+ and LT3265EDD, MP5418GQG-Z uniquely combines programmable negative LDO control (via CTL), ultra-low IQ (220 μA), and dual-rail integration in a 1.4 mm × 1.8 mm footprint - essential for space-constrained, battery-sensitive optical and RF applications requiring dynamic bias tuning.

Availability

MP5418GQG-Z is available at Aetrix Electronics and suitable for optical transceivers, RF power amplifiers, and portable sensor instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP5418GQG-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 MP5418 belongs to MPS's high-efficiency, ultra-compact DC/DC converter product line, designed specifically for space- and power-constrained portable and optical systems requiring dual negative rails with programmable regulation.

FAQ

What is the maximum allowable output current for MP5418GQG-Z?

The MP5418GQG-Z supports up to 200 mA total output current, shared between VOUT1 and VOUT2. At 60 mA load on VOUT2, typical dropout voltage is 20–80 mV depending on input voltage and temperature. The charge pump current limit is 1 A peak, but sustained output is thermally limited by the QFN-10 package's 1.47 W power dissipation rating at +25°C ambient.

How does the CTL pin set VOUT2 voltage?

The CTL pin is a high-impedance analog input that directly defines VOUT2 as −1×VCTL. For example, applying 1.25 V to CTL yields VOUT2 = −1.25 V. The regulator maintains this relationship with ±1% accuracy at room temperature and ±2% over −40°C to +125°C, enabling precise DAC-based bias control without external resistors or feedback networks.

Can MP5418GQG-Z operate with input voltages below 2.3 V?

No. The MP5418GQG-Z has a guaranteed under-voltage lockout (UVLO) rising threshold of 2.2–2.3 V. Operation below 2.3 V is not specified and may result in unstable regulation, erratic charge pump switching, or failure to enable. The device remains disabled until VIN exceeds the UVLO threshold, with 100–260 mV hysteresis to prevent oscillation near the threshold.

What capacitor types are recommended for CIN, CFLY, and COUT?

X5R or X7R ceramic capacitors are mandatory. Recommended values: 4.7 μF for CIN, CFLY, COUT1, and COUT2. Larger COUT2 (up to 10 μF) improves transient response and reduces noise. Avoid Y5V/Z5U dielectrics due to severe capacitance loss over temperature and bias, which compromises regulation stability and ripple performance.

Does MP5418GQG-Z provide reverse current protection?

No. The MP5418GQG-Z lacks integrated reverse current blocking. When VOUT1 or VOUT2 exceeds their respective source potentials (e.g., during hot-swap or backup power scenarios), current can flow backward through internal paths. External Schottky diodes or ideal diode controllers are required in systems demanding reverse polarity or backfeed protection.

How does the auto power-save mode affect switching frequency?

In auto power-save mode, the MP5418GQG-Z reduces charge pump switching frequency under light load to minimize switching losses and maintain low IQ. Frequency drops from up to 550 kHz (full load) to ~30 kHz (near-zero load), dynamically balancing efficiency and ripple. This behavior is intrinsic to the oscillator design and requires no external configuration.

Is the QFN-10 thermal pad electrically connected?

Yes. The exposed thermal pad on the MP5418GQG-Z QFN-10 package is internally connected to GND. It must be soldered to a solid PCB ground plane using ≥4 thermal vias (0.3 mm diameter) to achieve the specified θJA = 85 °C/W and ensure reliable thermal performance at full load.