Monolithic Power Systems Inc. MP3307GJ-Z

Overview

MP3307GJ-Z from Monolithic Power Systems is a non-synchronous white LED step-up driver in TSOT23-8 package, operating from 2.7V–5.5V input and delivering up to 24V open-load protection. It regulates LED current via external low-side sense resistor with 200mV ±1% feedback voltage, supports programmable switching frequency up to 2.2MHz, and integrates analog/PWM dimming control for video display backlighting.

For engineers reviewing the MP3307GJ-Z datasheet, MP3307GJ-Z pinout, MP3307GJ-Z application, or MP3307GJ-Z equivalent, key selection criteria include its 24V OVP threshold, dual-dimming interface (EN/PWML + PWMH), cycle-by-cycle current limit (1.6A), thermal shutdown (150°C), and TSOT23-8 footprint compatibility with space-constrained LCD backlight designs.

Technical Context

The MP3307GJ-Z uses peak-current-mode control with internal ramp compensation to stabilize operation above 50% duty cycle. Its error amplifier compares FB voltage against a precision 200mV reference, driving a low-side N-channel MOSFET (RDSON = 0.3–0.5Ω) to regulate LED current through external inductor and Schottky diode.

Protection logic includes real-time OVP monitoring at the OVP pin (24V threshold with 2V hysteresis), UVLO activation at 2.5V (200mV hysteresis), and thermal shutdown triggered at 150°C with 25°C hysteresis. Dimming is decoupled: EN/PWML enables PWM dimming (100Hz–2kHz), while PWMH accepts >20kHz signals for analog dimming via internal RC filtering.

Key Specifications

Pinout & Package

TSOT23-8 package: 2.9mm × 1.6mm × 0.85mm body, 0.65mm pitch, exposed pad for thermal dissipation (θJA = 100°C/W on 4-layer PCB).

Key Features

Applications

Equivalent & Alternatives

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

Compared with RT9397BZSP and LM3409MYX/NOPB, the MP3307GJ-Z uniquely combines programmable high-frequency switching, dual independent dimming interfaces, and fully integrated 24V OVP in a 2.9mm × 1.6mm package - making it optimal for compact, noise-sensitive, and functionally rich backlight systems.

Availability

MP3307GJ-Z is available at Aetrix Electronics and suitable for automotive infotainment displays, tablet backlight systems, and industrial HMI panels requiring stable component supply, full RoHS compliance, and guaranteed long-term availability.

Supply support for MP3307GJ-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 core expertise in DC/DC conversion, LED drivers, and motor control.

The MP3307 belongs to MPS's WLED backlight driver product line, designed specifically for space-constrained, high-reliability LCD backlight applications requiring precision current regulation, dual dimming modes, and robust fault protection.

FAQ

What is the minimum recommended inductor value for MP3307GJ-Z at 2.2MHz switching frequency?

The minimum inductance depends on input/output voltage, LED current, and efficiency. For typical 3.6V input and 12V output at 20mA, Equation (4) yields ≥2.2µH. MPS recommends 3.3µH (e.g., Coilcraft MSS5131-332) to ensure continuous conduction mode and margin against saturation at 1.6A peak current.

Can MP3307GJ-Z drive more than one LED string simultaneously?

Yes - it drives a single WLED string, but multiple MP3307GJ-Z ICs can be paralleled with synchronized FREQ resistors to drive independent strings. Each IC requires its own FB resistor and OVP divider; do not share SW or FB nodes between devices.

How does the 20ms shutdown timeout on EN/PWML function in practice?

A low-level signal lasting ≥20ms on EN/PWML forces full shutdown: internal bias rails deactivate, quiescent current drops to 1μA, and all switching ceases. Recovery requires reapplying a high-level signal - this feature enables hardware-based emergency cutoff without MCU intervention.

Is the 24V OVP threshold adjustable via external components?

No - the 24V OVP threshold is fixed and internally trimmed. The OVP pin senses output voltage via a resistive divider; the IC compares the divided voltage to an internal reference. To change trip point, adjust the divider ratio - e.g., 100kΩ:10kΩ sets 24V trip at OVP pin = 2.18V.

Does MP3307GJ-Z support I²C or other digital interfaces for configuration?

No - it is an analog-controlled LED driver with no digital interface. All configuration (frequency, current, dimming) is performed via external passive components (resistors, PWM signals) and pin-strapping. Configuration changes require hardware modification, not firmware updates.

What is the maximum allowable output voltage when using MP3307GJ-Z with a 5.5V input?

The absolute maximum VOUT is 40V per Absolute Maximum Ratings, but functional operation is limited by OVP (24V) and internal MOSFET breakdown. With 5.5V input, practical max output is ~22V before OVP triggers - sufficient for 6–7 white LEDs in series (3.2V each) under worst-case forward voltage variation.

How does the internal soft-start sequence affect system startup time?

The soft-start ramps the current reference from 0 to 200mV in 32 steps of 320μs each (total 10.24ms), limiting inrush current into the output capacitor. This prevents input voltage droop and avoids false triggering of UVLO or OCP during power-up, especially with large output capacitance.