Monolithic Power Systems Inc. MP3366GC-P

Overview

MP3366GC-P from Monolithic Power Systems is a 6-string, step-up white LED driver IC with integrated current sources, designed for LCD backlighting in tablets, notebooks, and terminal displays. It delivers up to 45mA per string, supports 3V–25V input, regulates output up to 45V, achieves ±1.5% inter-string current matching, and uses peak-current-mode PWM control at 600kHz.

For engineers reviewing the MP3366GC-P datasheet, MP3366GC-P pinout, MP3366GC-P application, or MP3366GC-P equivalent, key selection criteria include its mixed analog/PWM dimming architecture with 25% transfer point, 23.5–29.5kHz audible-noise-free dimming frequency, WLCSP-18 package footprint, and integrated open/short LED string protection.

Technical Context

The MP3366GC-P implements a fixed-frequency (600kHz), peak-current-mode boost converter with six independent, open-drain LED current sinks. Each string's current is set by a single external resistor on ISET (1.235V reference) and regulated with ≤500mV compliance voltage to minimize power loss.

Its dimming architecture combines analog amplitude control above 25% duty cycle and PWM duty scaling below 25%, automatically shifting output dimming frequency to 23.5–29.5kHz to eliminate audible noise. Protection includes recoverable OVP (programmable via OVP pin), OTP (150°C shutdown), cycle-by-cycle OCP, UVLO (2.57V rising), and per-string open/short detection using LEDX pin voltage thresholds (265mV UVLO, 5.5V OV).

Key Specifications

Pinout & Package

MP3366GC-P is housed in a WLCSP-18 package (1.35mm × 2.55mm), optimized for ultra-thin backlight modules. The die-attach side features 18 solder balls arranged in a 3×6 grid with pin 1 marked at top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 6-string LED driver applications.

Compared with RT9397B and ISL97693, the MP3366GC-P uniquely combines 6-string capability, ±1.5% matching, programmable OVP, and automatic 23.5–29.5kHz dimming frequency shift-making it optimal for mid-to-large LCD panels demanding reliability, uniformity, and silent operation.

Availability

MP3366GC-P is available at Aetrix Electronics and suitable for tablet backlighting, notebook display systems, and industrial terminal displays requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP3366GC-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 MP3366 product line targets high-efficiency, multi-string LED backlight drivers for portable and industrial displays, emphasizing precision current regulation, acoustic noise suppression, and robust fault protection.

FAQ

What is the minimum input voltage required for MP3366GC-P to start switching?

The MP3366GC-P enters operational mode only after VIN exceeds the UVLO rising threshold of 2.57V. Below this, the device remains in shutdown with quiescent current of 1μA. Startup also requires EN high and VCC ≥ 4.5V (if powered separately), or VIN ≥ 5.5V to enable the internal LDO.

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

MP3366GC-P guarantees ±1.5% inter-string current matching at TA = 25°C and ILED = 20mA. Over −40°C to +125°C junction temperature, total current error remains within ±4% due to matched internal current source design and 1.235V ±2.5% ISET reference tolerance.

Can MP3366GC-P drive more than 6 LED strings?

No. MP3366GC-P integrates exactly six dedicated current sinks (LED1–LED6) and cannot be paralleled or cascaded to increase string count. For >6 strings, multiple MP3366GC-P devices must be synchronized externally using shared PWM and EN signals.

What happens during an open-string fault, and how does recovery work?

When one or more strings open, the corresponding LEDX pins drop below 265mV. The IC disables those channels, maintains regulation on remaining strings, and resumes full operation automatically once the open connection is restored-no reset or EN toggle required.

Is the COMP pin compatible with standard Type II or Type III compensation networks?

Yes. COMP is the error amplifier output node and accepts standard Type II (capacitor + series RC) compensation. MPS recommends a 1nF capacitor from COMP to AGND plus a 10kΩ–100kΩ resistor in series for most 6-string, 20mA designs to ensure phase margin >45°.

Does MP3366GC-P support I²C or other digital interfaces for configuration?

No. MP3366GC-P is an analog-controlled LED driver with no digital interface. All configuration-including dimming mode, OVP threshold, and current level-is performed via external resistors (ISET, OVP divider) and the PWM/EN pins.

What is the maximum recommended PCB trace length between LX and PGND?

To minimize EMI and switching losses, the LX-to-PGND loop (including inductor, diode, and input/output capacitors) must be kept under 8mm total perimeter. Longer traces increase radiated emissions and risk instability due to parasitic inductance coupling into COMP and AGND.