Monolithic Power Systems Inc. MP3304BDD-LF-P

Overview

MP3304BDD-LF-P from Monolithic Power Systems is a 26V over-voltage protected, 1.3A step-up white LED driver with 2.2MHz fixed switching frequency, 200mV feedback reference, and true PWM dimming up to 50kHz. It regulates LED current via external sense resistor in boost topology for backlighting applications powered by 3–6V inputs such as single-cell Li-ion or 5V rails.

For engineers reviewing the MP3304BDD-LF-P datasheet, MP3304BDD-LF-P pinout, MP3304BDD-LF-P application, or MP3304BDD-LF-P equivalent, key selection criteria include OVP threshold (26V), thermal shutdown (150°C), internal 1.3A switch current limit, QFN8 2×3mm package footprint, and compatibility with 250Hz–50kHz PWM dimming control on the EN pin.

Technical Context

The MP3304BDD-LF-P implements constant-frequency peak-current-mode boost regulation with a 2.2MHz oscillator and integrated 0.4Ω power MOSFET. Its error amplifier compares 200mV across R_SET to maintain precise LED current, while slope compensation prevents subharmonic oscillation above 50% duty cycle.

Open-load protection triggers shutdown when output exceeds 26V (B-grade), and UVLO disables operation below 2.25V input. The EN pin serves dual function: logic-level enable/disable with 5ms disable timer and direct PWM dimming interface requiring ≥2V amplitude square wave.

Key Specifications

Pinout & Package

MP3304BDD-LF-P uses an 8-pin QFN package (2mm × 3mm, 0.5mm pitch) with exposed thermal pad connected to GND. The package enables compact layout and efficient heat dissipation in space-constrained backlight designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP3304ADD-LF-P, the MP3304BDD-LF-P trades OVP headroom for tighter voltage margin in cost-sensitive mid-string-count applications; versus RT9397BZSP, it delivers full integration and smaller footprint at the expense of external switch flexibility.

Availability

MP3304BDD-LF-P is available at Aetrix Electronics and suitable for LCD panels, digital picture frames, and handheld computers requiring stable component supply, RoHS-compliant packaging, and guaranteed long-term availability in QFN8 format.

Supply support for MP3304BDD-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP3304 product line delivers highly integrated LED drivers optimized for space-constrained, efficiency-critical backlighting in portable and industrial displays-emphasizing low-noise PWM dimming, robust fault protection, and minimal external component count.

FAQ

What is the maximum number of white LEDs the MP3304BDD-LF-P can drive in series?

The MP3304BDD-LF-P supports up to 10 series white LEDs per string when using typical 3.2–3.6V forward voltage LEDs and a 5V input, constrained by its 26V OVP threshold and 24V maximum output swing. Total string count depends on parallel configuration and current sharing design.

Does the MP3304BDD-LF-P require an external Schottky diode?

Yes, an external Schottky diode (e.g., B0530 or B0540) is required in the boost topology to rectify the inductor current into the LED string. The IC integrates only the power MOSFET switch-not the flyback diode-so proper diode selection (≥500mA rating, low V_F) is essential for efficiency and reliability.

How is LED current accuracy affected by temperature and supply variation?

LED current accuracy is maintained within ±5% over –40°C to +85°C and ±2% across 3–6V input range, due to the tightly regulated 200mV ISET reference and internal current-limit circuitry. External R_SET tolerance and temperature coefficient dominate residual error.

Can the MP3304BDD-LF-P operate from a 3.3V input source?

Yes, the MP3304BDD-LF-P operates from 3V minimum input, making it compatible with 3.3V rails. However, output headroom decreases: at 3.3V input, maximum usable LED string voltage is ~20.7V (24V − 3.3V), limiting series LED count unless efficiency trade-offs are accepted.

What happens during an open LED string condition?

When an LED string opens, feedback voltage drops to zero, causing the controller to increase duty cycle until output voltage reaches the 26V OVP threshold. At that point, the IC shuts down completely and remains latched off until input power is cycled-preventing damage from uncontrolled voltage rise.

Is the exposed thermal pad electrically isolated?

No, the exposed pad is internally connected to GND and must be soldered to the PCB's ground plane. It serves both electrical grounding and thermal conduction functions; floating or misconnected pads degrade thermal performance and may cause instability or premature thermal shutdown.