Monolithic Power Systems Inc. MP3397ES-LF-P

Overview

MP3397ES-LF-P from Monolithic Power Systems is a 4-string, step-up white LED driver IC designed for large-size LCD panel backlighting. It delivers up to 350mA per string with 2.5% current matching accuracy, operates from 5V–28V input, and uses external MOSFET control via 14-pin gate drive output. It supports both external PWM and DC-input burst PWM dimming for precise brightness control in flat-panel displays.

For engineers reviewing the MP3397ES-LF-P datasheet, MP3397ES-LF-P pinout, MP3397ES-LF-P application, or MP3397ES-LF-P equivalent, key selection criteria include its programmable 150–500kHz switching frequency, open/short LED protection architecture, cascading capability for 8+ strings, and 16-pin SOIC package thermal performance (θJA = 80°C/W).

Technical Context

The MP3397ES-LF-P implements a peak-current-mode, fixed-frequency boost controller with four independent current-regulated channels. Each channel uses an internal open-drain current sink (LED1–LED4) with 390mV regulation voltage at 180mA, enabling tight string current matching without external op-amps.

It integrates a 6V linear regulator (VCC) for gate drive and internal logic, under-voltage lockout (4.2V threshold), thermal shutdown (150°C), and dual-dimming control: DBRT accepts 0.2–1.2V DC for linear duty-cycle mapping or external PWM (100Hz–20kHz), while BOSC sets internal dimming frequency via capacitor (1–2kHz typical with 2.2nF).

Key Specifications

Pinout & Package

MP3397ES-LF-P is housed in a 16-pin SOIC package (body width 3.9mm, lead pitch 1.27mm) with exposed pad not present; thermal resistance θJA = 80°C/W on 4-layer JEDEC PCB.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar white LED driver applications.

Compared with MPQ3397-AEC1, the MP3397ES-LF-P offers identical core functionality at lower cost and smaller qualification burden for non-automotive use; versus LM3409QMY/NOPB, it delivers true simultaneous 4-string regulation with <2.5% matching-critical for uniform backlighting where single-string alternatives require complex multiplexing and suffer from temporal flicker.

Availability

MP3397ES-LF-P is available at Aetrix Electronics and suitable for desktop LCD flat panel displays, 2D/3D LCD TVs, and industrial human-machine interfaces requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP3397ES-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.

The MP3397 product line targets large-format LCD backlighting applications, delivering high-accuracy multi-string LED current regulation with integrated protection and flexible dimming to replace discrete solutions in display power systems.

FAQ

What is the maximum total output current capability of MP3397ES-LF-P?

The MP3397ES-LF-P supports up to 350mA per string across four independent channels, yielding a maximum combined output current of 1.4A. This rating assumes proper thermal management (θJA = 80°C/W), adequate PCB copper area, and operation within the recommended junction temperature range of –40°C to +125°C. Derating applies above 85°C ambient.

Can MP3397ES-LF-P drive more than four LED strings?

Yes-MP3397ES-LF-P supports cascading: two or more units can operate in parallel from a single boost inductor by connecting their COMP and VCC pins. This configuration scales to eight or more strings while maintaining current matching and synchronized dimming, provided external PWM dimming mode is used for timing alignment.

How does open-string protection work on MP3397ES-LF-P?

Open-string protection uses the OVP pin and LEDX pin voltages: if a string opens, its LEDX pin drops below 196mV, triggering detection. The IC then disables that string while regulating remaining strings to maintain output voltage. If all strings open, the boost converter shuts down entirely to prevent uncontrolled voltage rise.

What is the minimum recommended input capacitance for stable operation?

The minimum recommended input capacitance is 4.7μF X5R/X7R ceramic in parallel with a 220μF electrolytic capacitor. This combination suppresses high-frequency switching noise and limits surge current from the 5–28V input supply, ensuring stable VCC regulation and preventing EN pin false triggering during transients.

Does MP3397ES-LF-P require an external MOSFET, and what are key selection criteria?

Yes-it drives an external N-channel MOSFET via the GATE pin. Key selection criteria include V_DS(MAX) ≥ 1.5× expected output voltage, R_DS(ON) low enough to limit conduction loss at peak inductor current, Q_G compatible with 4Ω source/2Ω sink drive strength, and thermal rating sufficient for RMS current under worst-case load conditions.

Is there a difference between MP3397ES-LF-P and MP3397ES-Z?

Yes: MP3397ES-LF-P denotes RoHS-compliant, lead-free packaging in tape-and-reel format (the "-LF" suffix), while MP3397ES-Z indicates standard tape-and-reel without explicit RoHS marking. Both share identical electrical specifications and SOIC16 packaging; the "-P" denotes packaging type per MPS ordering nomenclature.