Monolithic Power Systems Inc. MP2371DG-LF-P

Overview

MP2371DG-LF-P from Monolithic Power Systems is a monolithic 700kHz current-mode synchronous step-down DC/DC converter with integrated 0.3Ω high-side MOSFET, delivering 1.8A continuous output current across 4.5V–24V input range and adjustable 0.81V–15V output. It features cycle-by-cycle over-current protection, thermal shutdown, and stable operation with low-ESR ceramic capacitors - deployed in broadband communications power rails and battery charger pre-regulators.

For engineers reviewing the MP2371DG-LF-P datasheet, MP2371DG-LF-P pinout, MP2371DG-LF-P application, or MP2371DG-LF-P equivalent, key selection criteria include its fixed 700kHz switching frequency, 0.1μA shutdown quiescent current, 2.5A peak current limit, 2mm × 2mm QFN8 package thermal resistance (θJA = 80°C/W), and feedback reference voltage of 0.81V ±2%.

Technical Context

The MP2371 operates in current-mode control with internal slope compensation, enabling fast transient response and simplified loop stabilization. Its error amplifier compares FB voltage against a precision 0.81V bandgap reference, while the PWM comparator integrates sensed inductor current and ramp compensation to regulate duty cycle.

Bootstrap gate drive (BST pin) enables high-side MOSFET operation up to 95% duty cycle; under-voltage lockout (2.8V threshold with 150mV hysteresis) ensures reliable startup. Frequency foldback activates below 250mV FB voltage to limit power dissipation during short-circuit faults.

Key Specifications

Pinout & Package

MP2371DG-LF-P is housed in a thermally enhanced 2mm × 2mm QFN8 package with exposed thermal pad (JEDEC MO-229 VCCD-3 compliant). Pin 1 identification is marked by a corner chamfer or dot; the exposed pad must be soldered to PCB ground for optimal thermal performance (θJC = 16°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with RT6220AGQW and TPS562211, MP2371DG-LF-P offers superior thermal density (2mm × 2mm), lowest shutdown current (0.1μA), and built-in frequency foldback - making it optimal for space-limited, battery-backed, or fault-prone applications where reliability and size dominate.

Availability

MP2371DG-LF-P is available at Aetrix Electronics and suitable for broadband communications equipment, digital entertainment systems, and distributed power systems requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP2371DG-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, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2371 belongs to MPS's high-density DC/DC converter product line, engineered for compact, efficient point-of-load regulation in space-constrained industrial, telecom, and consumer electronics - emphasizing thermal efficiency, minimal external components, and robust fault protection.

FAQ

What is the minimum recommended output capacitor value for stable operation?

The MP2371DG-LF-P is stable with a 22µF X5R/X7R ceramic capacitor at the output. This value ensures adequate phase margin and keeps output voltage ripple below 20mV peak-to-peak under full 1.8A load. Lower values may cause instability or excessive ripple, especially with high ESR alternatives.

Can the MP2371DG-LF-P operate with an input voltage below 4.5V?

No - the absolute minimum operating input voltage is 4.5V per the datasheet's Recommended Operating Conditions. Below this, UVLO prevents startup, and internal bias circuitry cannot sustain regulation. Attempting operation at 4.2V or lower risks erratic behavior or failure to regulate.

Is an external bootstrap diode required for all applications?

An external bootstrap diode (e.g., IN4148) is optional and only recommended when V_OUT = 3.3V or 5V and duty cycle exceeds 65% (i.e., V_IN/V_OUT > 1.5). It improves gate drive margin and efficiency but is unnecessary for 12V_IN/3.3V_OUT or higher input ratios.

How does the frequency foldback function protect the device during overload?

When FB voltage drops below 250mV - indicating severe overload or short-circuit - the oscillator frequency reduces from 700kHz to 230kHz. This lowers average switching losses and peak junction temperature, allowing the device to sustain fault conditions longer without triggering thermal shutdown.

What is the maximum achievable output voltage with the MP2371DG-LF-P?

The maximum output voltage is 15V, limited by the absolute maximum rating of the FB pin (6V) and internal clamp circuitry. Exceeding 15V risks violating the FB pin voltage limit when using high-resistance feedback dividers, potentially damaging the error amplifier input stage.

Does the MP2371DG-LF-P support forced PWM mode at light loads?

No - the MP2371DG-LF-P operates exclusively in current-mode PWM without pulse-skipping or burst-mode capability. At light loads (<100mA), it maintains fixed-frequency operation, which increases light-load efficiency compared to burst-mode converters but raises standby current relative to hysteretic alternatives.

What PCB layout practices are critical for thermal performance?

Direct soldering of the exposed thermal pad to a minimum 100mm² internal or bottom-layer copper pour connected to GND is essential. Routing IN, SW, and GND traces over solid planes - not thin traces - and minimizing the SW-GND loop area reduces thermal resistance to 16°C/W (θJC) and prevents localized hot spots above 100°C at full load.