Monolithic Power Systems Inc. MP3304CDD-LF-Z

Overview

MP3304CDD-LF-Z from Monolithic Power Systems is a 36V, 1.3A step-up white LED driver IC with fixed 2.2MHz switching frequency, 200mV feedback reference voltage, and true PWM dimming up to 50kHz. It regulates LED current via external sense resistor in boost topology, supports up to 10 parallel LED strings (e.g., 3×10 WLEDs), and features open-load shutdown at 20V for backlighting in small LCD displays.

For engineers reviewing the MP3304CDD-LF-Z datasheet, MP3304CDD-LF-Z pinout, MP3304CDD-LF-Z application, or MP3304CDD-LF-Z equivalent, key selection criteria include OVP threshold (20V), ISET regulation accuracy (185–215mV), thermal shutdown (150°C), and QFN8 (2×3mm) package compatibility with high-frequency layout constraints.

Technical Context

The MP3304CDD-LF-Z implements constant-frequency peak-current-mode control with internal 1.3A MOSFET switch and stabilizing ramp compensation to prevent subharmonic oscillation above 50% duty cycle. Its error amplifier compares ISET voltage against a 200mV reference to regulate LED current.

It integrates EN pin dual-function logic: >5ms low-level assertion disables output, while 250Hz–50kHz square-wave input enables true PWM dimming without audible noise. Open-lamp protection triggers shutdown when LED string voltage exceeds 20V, and UVLO activates below 2.25V input.

Key Specifications

Pinout & Package

MP3304CDD-LF-Z is housed in an 8-pin QFN package (2mm × 3mm, 0.5mm pitch) with exposed thermal pad connected to GND. The package supports high-power density PCB layouts and requires controlled-impedance routing for SW and PGND paths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP3304CDD-LF-Z, MP3302DJ-LF-Z offers lower cost but reduced current drive and OVP margin, while RT9397BZSP delivers higher switching frequency at the expense of added external components and higher static power.

Availability

MP3304CDD-LF-Z 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 MP3304CDD-LF-Z 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 MP3304 product line targets space-constrained portable backlighting applications, delivering high-efficiency step-up conversion with integrated protection and precision current regulation for WLED arrays.

FAQ

What is the maximum number of white LEDs the MP3304CDD-LF-Z can drive?

The MP3304CDD-LF-Z supports up to 10 parallel strings of white LEDs. Each string may contain multiple series LEDs, limited by the 20V open-load protection threshold - e.g., 6×3.3V WLEDs (19.8V) is the practical maximum per string at room temperature. Total output current is constrained by the 1.3A internal switch rating and thermal limits.

Does the MP3304CDD-LF-Z require an external Schottky diode?

Yes, an external Schottky diode is required in the boost topology. The datasheet recommends devices like MBR0520 or B0530 (500mA rated, low V_F) placed between SW and the output capacitor. No internal diode is integrated; omitting it will prevent proper energy transfer and cause immediate failure.

How is LED current accuracy affected by temperature?

LED current regulation depends on the 200mV ISET reference, which has ±5% tolerance over –40°C to +85°C ambient. The ISET pin bias current (–600 to –300nA) introduces negligible error across temperature when using standard 1% metal-film resistors; total current error remains within ±7% over full operating range.

Can the MP3304CDD-LF-Z operate from a 3.3V input supply?

Yes - the MP3304CDD-LF-Z operates from 3V to 6V input. At 3.3V input, it can still drive 3×WLED strings (≈10V) with sufficient headroom, though efficiency drops ~5% versus 5V due to higher duty cycle. UVLO releases at 2.25V, ensuring reliable startup even with Li-ion discharge to 3.0V.

What layout practices prevent EMI in MP3304CDD-LF-Z designs?

Minimize the high-di/dt loop formed by SW → PGND → input capacitor → IN. Place the 10µF input ceramic cap within 3mm of IN/PGND pins. Use solid GND plane under exposed pad and route SW trace wide and short. Add RC filter (e.g., 10Ω + 100nF) on IN pin per Figure 3 to suppress conducted noise.

Is the EN pin compatible with 1.8V logic microcontrollers?

Yes - the EN pin has guaranteed turn-on threshold of 1.8V (min) and turn-off threshold of 0.4V (max), making it directly compatible with 1.8V GPIO without level-shifting. A 5ms debounce delay is built-in for noise immunity; no external timing components are needed for basic ON/OFF control.