Monolithic Power Systems Inc. MP1584EN-LF-P

Overview

MP1584EN-LF-P from Monolithic Power Systems is a non-synchronous step-down DC/DC converter IC with integrated 150 mΩ high-side MOSFET, delivering up to 3 A output current at 1.5 MHz switching frequency across a 4.5 V to 28 V input range. It employs current-mode control for fast transient response and features internal soft-start, programmable frequency (100 kHz–1.5 MHz), and thermal shutdown. Used in automotive power rails where wide VIN and EMI-sensitive environments (e.g., AM radio bands) require high-frequency operation.

For engineers reviewing the MP1584EN-LF-P datasheet, MP1584EN-LF-P pinout, MP1584EN-LF-P application, or MP1584EN-LF-P equivalent, key selection criteria include its 3 A continuous output capability, 100 µA quiescent current for battery systems, SOIC8E thermal performance (θJA = 50 °C/W), and absence of external current-sense resistor requirement.

Technical Context

The MP1584EN-LF-P implements variable-frequency peak-current-mode control with cycle-by-cycle current limiting and internal 0.8 V reference. Its oscillator uses an external resistor on the FREQ pin to set switching frequency between 100 kHz and 1.5 MHz, enabling EMI mitigation via high-frequency operation.

It integrates a bootstrap driver for the high-side MOSFET, requiring an external BST–SW capacitor and Schottky catch diode. The COMP pin serves as error amplifier output for loop compensation, while FB senses output voltage via resistive divider-no external current sense needed due to internal transconductance-based current limit.

Key Specifications

Pinout & Package

The MP1584EN-LF-P is housed in a thermally enhanced SOIC8E package (exposed pad) with θ_JA = 50 °C/W and θ_JC = 10 °C/W on a 4-layer PCB per JESD51-7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP1584EN-LF-P, MP2338DJ-LF-Z offers higher current and better thermal specs but requires layout review for startup behavior, while LM2678SD-5.0/NOPB provides fixed-output simplicity at the cost of frequency flexibility and thermal performance-making MP1584EN-LF-P optimal for 3 A, 1.5 MHz, and thermally constrained designs.

Availability

MP1584EN-LF-P is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC power modules, and portable test equipment requiring stable component supply with RoHS-compliant packaging and SOIC8E thermal reliability.

Supply support for MP1584EN-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 distribution through authorized partners.

The MP1584 belongs to MPS's high-voltage buck converter product line, engineered for robust operation in automotive and industrial environments where wide input range, EMI resilience, and thermal efficiency are critical.

FAQ

What is the maximum allowable input voltage for MP1584EN-LF-P?

The absolute maximum input voltage is +30 V, with recommended operating range from 4.5 V to 28 V. Exceeding 30 V risks permanent damage per Absolute Maximum Ratings. The device includes UVLO with 3.0 V rising threshold and 2.6 V falling threshold to prevent erratic operation during brownout.

Can MP1584EN-LF-P operate without an external Schottky diode?

No. The MP1584EN-LF-P is a non-synchronous buck converter and requires an external Schottky diode connected from SW to GND. The diode must have ≥28 V reverse voltage rating and ≥3 A average current rating; low forward voltage (e.g., <0.45 V) is essential for efficiency.

How is switching frequency set on MP1584EN-LF-P?

Frequency is set by connecting a resistor (R_FREQ) from the FREQ pin to GND. The relationship is f_SW(kHz) ≈ 180,000 / R_FREQ(kΩ). For 1.5 MHz, use R_FREQ ≈ 10 kΩ; for 500 kHz, use ≈ 36 kΩ. Values outside 10 kΩ–100 kΩ may cause instability or inaccurate frequency.

Does MP1584EN-LF-P support adjustable output voltage?

Yes. Output voltage is set via a resistive divider from V_OUT to FB, referenced to the internal 0.8 V feedback voltage. For example, 3.3 V output uses R1 = 127 kΩ and R2 = 40.2 kΩ. R2 should be ≤40 kΩ to sink the ~20 µA BS leakage current at no load.

Is thermal derating required for continuous 3 A operation?

Yes. At T_A = +85°C, maximum continuous output current drops to ~2.2 A due to thermal limits. With 2.5 W max power dissipation and θ_JA = 50 °C/W, junction temperature rises ~125°C above ambient-requiring adequate copper area on the exposed pad and airflow for full 3 A operation at high ambient.

What is the purpose of the BST pin and required external component?

BST supplies gate drive voltage to the internal high-side MOSFET via a bootstrap capacitor connected between BST and SW. A 0.1 µF ceramic capacitor is required; it charges when SW is near GND (during diode conduction) and powers the floating driver during high-side switch ON time.

Why does the datasheet state "NOT RECOMMENDED FOR NEW DESIGNS"?

MPS has introduced the MP2338 as a pin-compatible upgrade with higher current (4 A), lower R_DS(on), improved efficiency, and extended temperature range. MP1584EN-LF-P remains fully qualified and supported for existing designs and legacy production, but new designs should evaluate MP2338 for long-term supply and performance.