Monolithic Power Systems Inc. MP3310EQ-LF-P

Overview

MP3310EQ-LF-P from Monolithic Power Systems is a monolithic step-up white LED driver IC with true PWM dimming, 47V output capability, 1.3A internal switch current limit, and adjustable 300kHz–1.2MHz switching frequency. It regulates LED current via external ISET resistor, supports up to 12-series WLED strings, and integrates OVP, UVLO, thermal shutdown, and 0.3Ω internal MOSFET for LCD backlighting in compact portable displays.

For engineers reviewing the MP3310EQ-LF-P datasheet, MP3310EQ-LF-P pinout, MP3310EQ-LF-P application, or MP3310EQ-LF-P equivalent, key selection criteria include its 4.5–25V input range, 500mV LED current sense reference, 1.24V OVP threshold, 10-pin QFN-3×3mm package, and single-pin EN/DIM interface supporting 200Hz–2kHz PWM dimming without color shift.

Technical Context

The MP3310EQ-LF-P implements fixed-frequency peak-current-mode control with internal 5V LDO (VCC) powering gate drivers and analog circuitry. Its error amplifier compares LED current-derived voltage against a precise 500mV reference, generating COMP voltage that modulates switch duty cycle via PWM comparator and slope compensation.

OVP is programmable via resistive divider on OVP pin (1.24V threshold), while FSET sets switching frequency and ISET determines regulated LED current using I_LED = 4605V / R_ISET. The IC enters latch-off shutdown on open-load detection and resumes only after full enable cycle reset.

Key Specifications

Pinout & Package

MP3310EQ-LF-P is housed in a thermally enhanced 10-pin QFN package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad connected to GND for optimal power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RT9397BZSP and LM3409QMY/NOPB, MP3310EQ-LF-P uniquely combines adjustable frequency, true PWM dimming, programmable OVP, and integrated 5V LDO in a 3×3mm QFN-reducing component count by ≥4 and enabling faster design iteration for portable display backlighting.

Availability

MP3310EQ-LF-P is available at Aetrix Electronics and suitable for LCD panels, digital picture frames, and handheld computer displays requiring stable component supply, RoHS-compliant packaging, and production-ready lead times.

Supply support for MP3310EQ-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 power management ICs, founded in 1997 and headquartered in Kirkland, Washington.

The MP3310 belongs to MPS's white LED driver product line, engineered specifically for energy-efficient, compact backlight solutions in portable and space-constrained display systems with stringent dimming fidelity requirements.

FAQ

What is the maximum number of white LEDs the MP3310EQ-LF-P can drive in series?

The MP3310EQ-LF-P supports up to 12-series white LEDs, based on its 47V maximum output voltage rating and typical white LED forward voltage of ≈3.8V. At 12×3.8V = 45.6V, it maintains 1.4V headroom for regulation margin and ripple, ensuring stable current control even with V_f variation across temperature and binning.

Does MP3310EQ-LF-P require an external Schottky diode?

Yes, MP3310EQ-LF-P requires an external Schottky diode (e.g., B160 or B0540) connected between SW and the output capacitor. The IC integrates only the high-side power MOSFET; the diode provides the freewheeling path during switch-off periods and must be rated for ≥47V reverse voltage and ≥1.3A average current.

Can MP3310EQ-LF-P operate with input voltage below 5.5V?

Yes-when VIN is below 5.5V, the internal VCC LDO cannot regulate. In this case, VCC must be tied directly to VIN or supplied externally with a stable 5V source. The datasheet explicitly states this configuration is required to power internal gate drivers and control circuitry reliably.

How is the LED current accuracy affected by temperature?

LED current regulation maintains ±3% total error over –20°C to +85°C ambient, including initial tolerance, temperature drift, and line/load variation. The 500mV internal reference exhibits <100ppm/°C drift, and the ISET resistor's thermal coefficient dominates residual error-using a 50ppm/°C metal-film resistor achieves best-in-class stability.

What happens during an open-LED condition?

During open-LED fault, the output voltage rises until the OVP pin voltage reaches 1.24V, triggering latch-off shutdown. The IC stops switching and holds SW low. Recovery requires cycling EN/DIM low for >10ms (disable timer) then re-enabling-no automatic retry to prevent repeated stress on output components.

Is the exposed thermal pad electrically isolated?

No-the exposed pad on the QFN-10 package is internally connected to GND and must be soldered to a dedicated PCB GND plane. It serves both thermal conduction (θ_JC = 12°C/W) and electrical grounding; floating or connecting it to another net violates absolute maximum ratings and risks device failure.

Can MP3310EQ-LF-P support analog dimming in addition to PWM?

No-MP3310EQ-LF-P supports true PWM dimming only via the EN/DIM pin. It does not implement analog (DC) dimming or current-scaling methods. Attempting to apply variable DC voltage to EN/DIM will not modulate brightness and may violate input voltage thresholds, causing erratic enable/disable behavior.