Monolithic Power Systems Inc. MP2361DQ-LF-P

Overview

MP2361DQ-LF-P from Monolithic Power Systems is a monolithic 2A, 23V input, 1.4MHz synchronous step-down DC/DC converter with integrated 0.18Ω high-side MOSFET and internal bootstrap diode. It delivers stable output voltage adjustable from 0.92V to 16V, supports 4.75–23V input range, achieves up to 90% efficiency, and includes cycle-by-cycle over-current protection and thermal shutdown - deployed in DSL modems, battery chargers, and distributed power systems.

For engineers reviewing the MP2361DQ-LF-P datasheet, MP2361DQ-LF-P pinout, MP2361DQ-LF-P application, or MP2361DQ-LF-P equivalent, key selection criteria include its QFN10 (3mm × 3mm) package with exposed thermal pad, programmable soft-start, 20μA shutdown current, fixed 1.4MHz switching frequency, and compatibility with low-ESR ceramic output capacitors.

Technical Context

The MP2361DQ-LF-P employs peak current-mode control with slope compensation to ensure stability across wide duty cycles and load transients. Its transconductance error amplifier (GEA = 630–1230 μA/V) drives the COMP pin, enabling precise loop compensation via external RC networks.

It integrates a 0.18Ω high-side switch and 10Ω low-side switch, supporting continuous 2A output with internal bootstrap capacitor charging. The 1.4MHz oscillator enables compact magnetics, while frequency foldback below 400mV FB voltage improves short-circuit robustness.

Key Specifications

Pinout & Package

MP2361DQ-LF-P uses a thermally enhanced QFN10 (3mm × 3mm) package with exposed pad soldered to PCB ground plane for optimal thermal dissipation (θ_JA = 50°C/W). Pin 1 is marked by a dot; pins 1 and 3 are no-connect (NC); pin 6 is GND and must be tied directly to the exposed pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2362DQ-LF-Z, MP2361DQ-LF-P trades 1A output headroom for lower cost and identical footprint; versus RT7272BGJ6F, it delivers superior integration, higher frequency, and simpler layout - making it optimal for mid-power industrial and communications POL applications.

Availability

MP2361DQ-LF-P is available at Aetrix Electronics and suitable for DSL modems, battery charger pre-regulators, and distributed power systems requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP2361DQ-LF-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, headquartered in California and serving global industrial, telecom, and consumer markets since 1997.

The MP2361 product line delivers highly integrated, thermally optimized DC/DC converters targeting space-constrained, efficiency-critical applications such as broadband access equipment and portable power systems.

FAQ

What is the minimum recommended input capacitance for MP2361DQ-LF-P?

The datasheet specifies a 10μF ceramic input capacitor plus a 0.1μF high-frequency bypass capacitor placed adjacent to the IN and GND pins. This combination suppresses high-frequency switching noise and maintains stable input voltage under dynamic load conditions. For 2A operation at 23V input, RMS current rating should exceed 1A.

Can MP2361DQ-LF-P operate with an output voltage below 0.92V?

No - the internal bandgap reference is trimmed to 0.92V, and the feedback comparator is designed for regulation only at or above this voltage. Attempting sub-0.92V operation results in loss of regulation and uncontrolled output collapse. For lower voltages, a different converter with adjustable reference or external error amplifier is required.

Is the exposed thermal pad on the QFN10 package electrically connected internally?

Yes - the exposed pad is internally connected to GND and must be soldered to a dedicated PCB copper pour tied to the main ground plane. This connection is essential for both thermal performance (reducing θ_JA from 50°C/W to ~35°C/W with 2-in² copper) and electrical noise suppression.

Does MP2361DQ-LF-P support forced PWM mode or only PFM at light loads?

MP2361DQ-LF-P operates exclusively in forced PWM mode across all load conditions - no pulse-frequency modulation (PFM) or diode emulation. This ensures constant 1.4MHz switching, predictable EMI spectrum, and consistent transient response regardless of load current.

What is the maximum allowable duty cycle and how is it enforced?

The maximum duty cycle is 70%, enforced by internal circuitry that clamps COMP pin voltage to prevent extended high-side conduction. This limit prevents bootstrap capacitor discharge failure and ensures reliable gate drive under high-V_OUT/V_IN ratios (e.g., 16V out from 23V in).

How does the frequency foldback function activate during overload?

When FB voltage drops below 400mV - indicating severe overload or short-circuit - the frequency foldback comparator reduces oscillator frequency from 1.4MHz to 210kHz. This lowers average switch current, reduces power dissipation, and enhances fault tolerance without triggering immediate shutdown.

Can the EN pin be used for input voltage sequencing in multi-rail systems?

Yes - the EN pin's 2.50V enable threshold and 210mV hysteresis allow precise power-up sequencing. By connecting EN to a resistor divider from a higher-priority rail (e.g., 3.3V), MP2361DQ-LF-P can be configured to turn on only after that rail stabilizes, preventing back-powering or latch-up.