Monolithic Power Systems Inc. MPM3840GQV-P

Overview

MPM3840GQV-P from Monolithic Power Systems is a fully integrated, synchronous step-down DC/DC power module with internal MOSFETs and inductor, delivering 4A continuous output current from a 2.8V–5.5V input. It regulates output down to 0.6V using constant-on-time (COT) control, features 1.2MHz switching frequency, 40μA quiescent current, and integrated power-good (PG) and enable (EN) functions-designed for space-constrained Li+-powered portable systems.

For engineers reviewing the MPM3840GQV-P datasheet, MPM3840GQV-P pinout, MPM3840GQV-P application, or MPM3840GQV-P equivalent, key selection considerations include its QFN-20 (3mm×5mm×1.6mm) package with thermal-enhanced GND pads, COT-based transient response, dual-mode (PWM/PFM) operation via MODE pin, and built-in protections including cycle-by-cycle OCP, hiccup-mode SCP, and thermal shutdown.

Technical Context

The MPM3840GQV-P implements a constant-on-time (COT) control architecture with input-voltage feed-forward, enabling stable 1.2MHz switching across 2.8V–5.5V input and 0.6V–3.3V output ranges. Its internal high-side (25mΩ) and low-side (12mΩ) MOSFETs drive an integrated 0.47μH inductor, eliminating external magnetics.

It supports dynamic output regulation via analog voltage injection on the MODE pin (0.6V–1.1V), delivers power-good status with 140μs delay and 500kΩ internal pull-up, and enables pre-biased start-up with 1.5ms soft-start. Protection includes cycle-by-cycle current limiting (5.5A peak), short-circuit hiccup recovery, and thermal shutdown at 150°C with 20°C hysteresis.

Key Specifications

Pinout & Package

MPM3840GQV-P is housed in an ultra-small, thermally enhanced QFN-20 package (3mm × 5mm × 1.6mm) with exposed thermal pad. The package integrates power MOSFETs, driver, controller, and 0.47μH inductor, requiring only input/output capacitors and FB resistors for full functionality.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM10504S and RTM2020B, the MPM3840GQV-P uniquely balances ultra-compact integration, analog-dynamic regulation, and best-in-class light-load efficiency - making it optimal for space- and runtime-constrained embedded systems where digital interfaces or fixed-frequency rigidity are unnecessary.

Availability

MPM3840GQV-P is available at Aetrix Electronics and suitable for portable medical sensors, industrial IoT edge nodes, network interface cards, and low-voltage FPGA core supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MPM3840GQV-P 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 over two decades of leadership in DC/DC conversion, motor drivers, and LED lighting solutions.

The MPM3840 belongs to MPS's integrated power module product line, engineered specifically for space-constrained, battery-operated applications demanding high efficiency, fast transient response, and minimal external components.

FAQ

What is the maximum output current and under what conditions is it guaranteed?

The MPM3840GQV-P delivers 4A continuous output current at TA = +25°C on a 4-layer PCB with adequate copper pour and airflow. Derating begins above 85°C ambient due to thermal limits; full 4A is maintained up to TJ = 125°C with proper thermal design per θJA = 46°C/W.

Can the output voltage be dynamically adjusted without changing external resistors?

Yes - applying 0.6V to 1.1V to the MODE pin dynamically adjusts the internal reference voltage from 0.35V to 0.6V (±3% typical accuracy), enabling real-time VOUT tuning while retaining the same FB resistor divider - ideal for adaptive power schemes in FPGA or SoC applications.

Does the device support startup into a pre-biased output?

Yes - the MPM3840GQV-P includes pre-biased start-up capability. When the FB voltage exceeds the internal soft-start ramp at power-on, both high-side and low-side FETs remain off until the ramp crosses the FB level, preventing reverse current and ensuring safe hot-swap operation.

What type of input capacitor is recommended and why?

A 22μF X5R/X7R ceramic capacitor placed adjacent to VIN and GND is recommended. Its low ESR minimizes input ripple and high-frequency noise, while its stable capacitance over temperature and bias ensures consistent performance - critical for COT control stability and EMI compliance.

How does the power-good (PG) signal behave during fault conditions?

PG goes low immediately upon undervoltage (VFB < 0.85×VREF) or overvoltage (VFB > 1.15×VREF), with a 140μs delay before asserting high after regulation is restored. During thermal shutdown or OCP latch, PG remains low until normal operation resumes - providing reliable sequencing and fault indication.

Is an external compensation network required for stability?

No - the MPM3840GQV-P uses constant-on-time control with inherent loop stability and requires no external compensation components. Stability is ensured with standard low-ESR ceramic output capacitors (e.g., 22μF ×2); adding extra capacitance or ESR may degrade transient response.

What is the purpose of the RAMP pin and how should it be configured?

The RAMP pin connects to a 10pF–47pF ceramic capacitor between OUT and RAMP to inject controlled slope compensation, improving transient response and reducing output voltage undershoot during large load steps - especially beneficial in high-current, low-VOUT applications like 1.0V FPGA cores.