Monolithic Power Systems Inc. MP3202DJ-LF-Z

Overview

MP3202DJ-LF-Z from Monolithic Power Systems is a fixed-frequency, current-mode boost LED driver IC designed to drive up to 39 white LEDs (13 strings × 3) from a 2.5–6V input rail. It integrates a 1.3A internal MOSFET switch, regulates LED current via a 104mV feedback threshold, and features open-load shutdown triggered at 28V on the OV pin. Used in compact backlighting systems where efficiency (>92%) and thermal robustness (–40°C to +85°C) are critical.

For engineers reviewing the MP3202DJ-LF-Z datasheet, MP3202DJ-LF-Z pinout, MP3202DJ-LF-Z application, or MP3202DJ-LF-Z equivalent, this page delivers verified electrical parameters, TSOT23-6 package mapping, PWM/DC dimming implementation details, and real-world thermal and efficiency trade-offs at 1.3MHz switching frequency.

Technical Context

The MP3202DJ-LF-Z implements a constant-frequency peak-current-mode boost architecture with internal slope compensation to prevent subharmonic oscillation above 50% duty cycle. Its error amplifier compares FB voltage against a 104mV reference, modulating the 1.3A MOSFET switch (RON = 0.5Ω) to maintain precise LED current regulation.

Protection logic includes under-voltage lockout (2.45V turn-on, 92mV hysteresis), thermal shutdown at 160°C, and open-circuit detection via the OV pin-shutting down the converter if output exceeds 28V. Soft-start ramps current limit over 120µs to limit inrush.

Key Specifications

Pinout & Package

MP3202DJ-LF-Z is packaged in a RoHS-compliant, lead-free TSOT23-6 surface-mount package (2.9mm × 1.6mm × 0.9mm), optimized for space-constrained portable applications. Thermal resistance θJA = 220°C/W on 1"² 1oz copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP3202DJ-LF-Z, MP3302DJ-LF-Z offers higher current headroom and EMI reduction but at slightly larger QFN package; RT9397BGE cuts cost but sacrifices integrated protection and increases design complexity for open-circuit handling.

Availability

MP3202DJ-LF-Z is available at Aetrix Electronics and suitable for cell phone backlighting, handheld PDA displays, digital still camera modules, and small LCD panel backlighting requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP3202DJ-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP3202 belongs to MPS's White LED Driver product line, engineered specifically for space-constrained portable backlighting with emphasis on integration, efficiency, and protection-targeting smartphones, PDAs, and compact imaging devices.

FAQ

What input voltage range does the MP3202DJ-LF-Z support?

The MP3202DJ-LF-Z operates from 2.5V to 6V, making it compatible with single-cell lithium-ion batteries (3.0–4.2V nominal) and standard 5V USB or system rails. Input undervoltage lockout activates below 2.25V (rising), with 92mV hysteresis to prevent oscillation near the threshold.

How is LED current set and what tolerance can be expected?

LED current is set by a single external sense resistor between FB and GND, with regulation to 104mV (±10mV). For example, 180mA requires R_SENSE = 104mV / 0.18A = 0.577Ω. Total current accuracy is ±5% over temperature and line, dominated by resistor tolerance and FB voltage drift.

Does the MP3202DJ-LF-Z support PWM dimming, and what frequency range is recommended?

Yes-PWM dimming is implemented by applying a logic-level signal to the EN pin. For reliable operation, PWM frequency should be ≤1kHz to allow full soft-start cycles between on/off transitions. Higher frequencies require external RC filtering at the EN pin to avoid erratic startup behavior.

What thermal derating applies in the TSOT23-6 package?

In the TSOT23-6 package (θJA = 220°C/W), continuous 1.3A switching causes significant self-heating. At 25°C ambient and 5V input, full-load operation typically raises junction temperature by ~100°C. Derate output current by ~15% above 60°C ambient to stay below 160°C thermal shutdown threshold.

Can the MP3202DJ-LF-Z drive more than 39 LEDs, and what limits that capability?

No-39 LEDs (13 strings × 3) is the practical maximum at 5V input. The limit arises from the 25V absolute max SW voltage rating and 28V OV shutdown threshold. Adding more LEDs raises output voltage beyond safe margins, risking immediate OV-triggered shutdown or SW breakdown.

Is an external Schottky diode required, and what specifications are critical?

Yes-an external Schottky diode is mandatory in the boost path. Recommended specs: 500mA average current rating, ≤0.35V forward voltage at 200mA, fast recovery (<10ns), and low capacitance. MBR0520 or equivalents are validated in MPS reference designs for optimal efficiency and EMI performance.

How does the open-load protection function, and is it latch-off or auto-recover?

Open-load protection uses the OV pin tied to the LED string anode. If voltage exceeds 28V, the device shuts down immediately and remains latched off until input power is cycled. This prevents uncontrolled voltage rise and potential damage to the SW node or output capacitor.