Monolithic Power Systems Inc. MP2490DS-LF-P

Overview

MP2490DS-LF-P from Monolithic Power Systems is a 36V, 1.5A synchronous step-down DC/DC converter with programmable output current limit via ISP/ISN sense inputs, fixed 700kHz switching frequency, and 0.25Ω internal MOSFET. It operates from 4.5V–36V input, delivers adjustable 0.8V–15V output, and supports USB power supplies and automotive cigarette lighter adapters.

For engineers reviewing the MP2490DS-LF-P datasheet, MP2490DS-LF-P pinout, MP2490DS-LF-P application, or MP2490DS-LF-P equivalent, this page provides verified package mapping (SOIC-8), confirmed current-sense architecture (100mV threshold), thermal shutdown behavior (150°C trip), cycle-by-cycle overcurrent protection, and real-world efficiency data (95% @ 500mA, Vo=5V).

Technical Context

The MP2490DS-LF-P implements a current-mode buck topology with integrated high-side MOSFET and bootstrap gate driver. Its error amplifier regulates output voltage via FB pin (0.805V typical reference), while a dedicated current-limit loop compares ISP–ISN differential voltage against a 100mV threshold to enforce programmable load current limiting.

It features fixed-frequency PWM control at 700kHz (±140kHz tolerance), soft-start via external SS capacitor, open-drain PGOOD monitoring (90% VFB threshold), and dual protection: cycle-by-cycle current limiting and thermal shutdown at 150°C. EN pin functionality is disabled in SOIC-8 variant per datasheet specification.

Key Specifications

Pinout & Package

MP2490DS-LF-P is housed in an 8-pin SOIC package (body size 3.9mm × 4.9mm, lead pitch 1.27mm) with exposed thermal pad not present - unlike QFN variant. Pin 1 is marked by notch or bevel; GND (Pin 2) serves as primary voltage reference and thermal path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2490DS-LF-P, MP2491DS-LF-Z offers higher current and EN control at cost of slightly reduced efficiency at light loads, while LM5164QDDARQ1 trades current capability and integrated current sensing for AEC-Q100 compliance and extended input voltage - making MP2490DS-LF-P optimal for cost-sensitive industrial USB and accessory power where programmable current limit is essential.

Availability

MP2490DS-LF-P is available at Aetrix Electronics and suitable for USB power supplies, automotive cigarette lighter adapters, and linear charger power supplies requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP2490DS-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 across Asia and North America and global distribution.

The MP2490 belongs to MPS's industrial-grade buck converter product line, engineered for robust operation in automotive, industrial, and consumer power applications where wide input range, programmable current limiting, and minimal external components are critical.

FAQ

What is the function of the SS pin on MP2490DS-LF-P?

The SS (Soft-Start) pin controls startup ramp rate and compensates the current-limit loop. An external capacitor (typically 100nF) connected from SS to GND sets the soft-start duration and establishes the dominant pole for current regulation bandwidth (<1kHz). It also pulls down during overcurrent events to reduce duty cycle and enforce constant-current mode.

Does MP2490DS-LF-P support enable functionality?

No. The EN pin is only implemented in the QFN10 (MP2490DQ) variant. The SOIC-8 MP2490DS-LF-P lacks EN functionality - it powers up whenever VIN is within 4.5V–36V and remains active until input drops below UVLO threshold (3.3V typ). System-level enable must be implemented externally via VIN switching.

How is output current limit programmed on MP2490DS-LF-P?

Current limit is set by the differential voltage between ISP and ISN pins. When V_ISP – V_ISN reaches 100mV (typ), the current-limit loop activates and regulates output current. For sense-resistor implementation: I_LIM = 0.1V / R_SENSE. For DCR sensing, a resistor network scales inductor DCR voltage to match the 100mV threshold.

What is the purpose of the PGOOD pin?

PGOOD is an open-drain output that signals valid regulation: it stays high (when pulled up externally) only when FB voltage is ≥90% of 0.805V (i.e., ≥0.72V). It asserts low during startup, output overvoltage, undervoltage, or thermal shutdown - enabling safe power sequencing and fault detection in host systems.

Can MP2490DS-LF-P operate with ceramic output capacitors?

Yes. The MP2490DS-LF-P is explicitly designed for stability with low-ESR ceramic capacitors (X5R/X7R dielectrics). Its control loop compensates for ceramic capacitance characteristics, eliminating need for aluminum or tantalum capacitors and improving reliability, temperature stability, and lifetime in demanding environments.

What thermal performance can be expected in SOIC-8 package?

In SOIC-8, θ_JA = 90°C/W and θ_JC = 45°C/W. At 25°C ambient and 1.5A load, junction temperature rise is ~135°C (1.5A² × 0.25Ω × 90°C/W), reaching ~160°C - triggering thermal shutdown. Derating to ≤1.0A or adding copper pour significantly improves thermal margin; datasheet specifies 1.39W max continuous dissipation at T_A = 25°C.

Is the 700kHz switching frequency adjustable?

No. MP2490DS-LF-P uses a fixed internal oscillator at 700kHz (typ), with ±20% variation over temperature and supply. There is no external frequency programming option. During fault conditions (e.g., FB < 250mV), frequency folds back to 200kHz to reduce stress and improve short-circuit recovery.