Monolithic Power Systems Inc. MP2341GTL-Z

Overview

MP2341GTL-Z from Monolithic Power Systems is a synchronous step-down white LED driver IC with integrated 125mΩ high-side and 75mΩ low-side MOSFETs, delivering up to 2A continuous output current at 1MHz switching frequency across a 4.2V–24V input range. It regulates LED current via 100mV feedback reference and supports analog dimming (50:1 ratio) and PWM dimming (1000:1 ratio) for infrared and backlight applications.

For engineers reviewing the MP2341GTL-Z datasheet, MP2341GTL-Z pinout, MP2341GTL-Z application, or MP2341GTL-Z equivalent, key selection criteria include its SOT583 package thermal performance (θJA = 55°C/W), forced PWM mode operation, open LED and thermal shutdown protection, and dual-dimming interface (EN/DIM and PDIM pins).

Technical Context

The MP2341GTL-Z employs peak current-mode control with a fixed 1MHz oscillator, enabling fast transient response and stable regulation under varying load and line conditions. Its internal error amplifier compares FB voltage against a precise 100mV reference to generate COMP voltage, directly controlling HS-FET on-time and regulating LED current.

It integrates bootstrap circuitry for high-side gate drive, with BST capacitor charging from SW node and regulated 3.3V BST-to-SW bias. Protection functions include cycle-by-cycle OCP (4A HS limit), hiccup-mode recovery, open LED detection via FB threshold monitoring, and thermal shutdown at 150°C with 20°C hysteresis.

Key Specifications

Pinout & Package

SOT583 is an 8-pin, thermally enhanced, surface-mount package with exposed pad for improved heat dissipation. Pin 1 is marked by a dot; top marking includes product code (BCE), year (Y), and lot (LLL). MSL Level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2341GQL-Z, the MP2341GTL-Z trades automotive qualification for lower cost and broader commercial availability; versus LT3466-1EDD, it delivers 67% higher output current, dual-dimming flexibility, and integrated fault protection - making it superior for compact, high-brightness LED systems.

Availability

MP2341GTL-Z is available at Aetrix Electronics and suitable for infrared LED drivers, handheld computer backlighting, and flashlight power management requiring stable component supply, consistent SOT583 packaging, and guaranteed dimming performance across temperature.

Supply support for MP2341GTL-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 power management ICs, with over two decades of expertise in DC-DC conversion, LED drivers, and motor control solutions.

The MP2341 belongs to MPS's high-efficiency LED driver product line, designed specifically for space-constrained, thermally demanding applications requiring precise constant-current regulation and flexible dimming control.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MP2341GTL-Z features an under-voltage lockout (UVLO) with a rising threshold of 4.0V ±0.2V and 350mV hysteresis. Reliable startup occurs only when VIN exceeds 4.2V, and operation ceases if VIN drops below 3.7V. This ensures stable bias generation and gate drive for internal MOSFETs.

How does the dual-dimming interface (EN/DIM and PDIM) interact during simultaneous use?

When both EN/DIM voltage (0.66–1.57V) and PDIM PWM signal are active, LED current equals I_SET × DUTY_PDIM, where I_SET is the current determined by EN/DIM voltage and FB resistor. This enables fine-grained brightness control without compromising dimming linearity or introducing ripple.

Can the MP2341GTL-Z drive more than two white LEDs in series?

Yes - the MP2341GTL-Z supports output voltages up to 20V (or 0.9×VIN), enabling up to nine IR LEDs (1.2V each) or six white LEDs (3.0V each) in series. The FB reference remains fixed at 100mV, so R_SENSE must be recalculated per I_LED = 0.1V / R_SENSE regardless of string count.

What is the purpose of the RT resistor in the typical application schematic?

The RT resistor (1kΩ) forms an RC filter with the FB trace capacitance to suppress high-frequency noise coupling into the feedback node. It is required only when FB trace length exceeds 5mm or when layout constraints introduce noise; omission risks instability or false open-LED triggering.

Does the MP2341GTL-Z support burst-mode operation at light loads?

No - the MP2341GTL-Z operates exclusively in forced PWM mode, maintaining fixed 1MHz switching regardless of load. This eliminates low-frequency switching artifacts and ensures predictable EMI behavior, unlike skip-cycle or burst-mode converters that modulate frequency under light load.

What is the maximum allowable BST capacitor value and why is it constrained?

The BST capacitor must be 1µF ceramic (X5R/X7R); values exceeding 1µF risk overstressing the internal bootstrap diode during startup and cause excessive inrush current into the BST node. Larger capacitors also slow bootstrap recharge, potentially causing HS-FET dropout at high duty cycles.

How does open LED protection behave when the FB pin is disconnected?

If the FB network opens (e.g., sense resistor failure), the FB voltage rises above 145mV, triggering open LED protection. The IC halts switching, holds SW low, and enters latch-off state until EN/DIM is cycled. No auto-restart occurs - manual reset via EN/DIM toggle is required.