Monolithic Power Systems Inc. MP1519DQ-LF-Z

Overview

MP1519DQ-LF-Z from Monolithic Power Systems is a fully automatic 4-channel white LED driver IC using a 1x/1.5x/2x switched-capacitor charge pump architecture to power four 3.35V_F LEDs from 2.5–5.5V input (e.g., single Li-Ion). It delivers 20mA per channel with ≤5.0% current matching, >93% peak efficiency, and supports PWM/analogue dimming. Used in compact backlighting for handheld displays.

For engineers reviewing the MP1519DQ-LF-Z datasheet, MP1519DQ-LF-Z pinout, MP1519DQ-LF-Z application, or MP1519DQ-LF-Z equivalent, key selection criteria include automatic mode switching thresholds (VBATT 2.8V/3.1V/3.6V/3.8V), 1.25V internal reference for LED current setting, soft-start/soft-switching behavior, and QFN16 thermal resistance (θ_JA = 60°C/W).

Technical Context

The MP1519 employs a dual-capacitor charge pump with automatic mode selection between 1× (direct pass-through), 1.5× (fractional boost), and 2× (voltage doubling) based on real-time battery voltage and LED forward voltage requirements. Each of the four LED channels uses independent current-source regulation referenced to a 1.25V bandgap.

It integrates battery sensing, fault detection (open-LED), and supervisory logic that maintains <1μA shutdown current after 30μs EN low pulse and LEDC discharge. Operation is constant-frequency (1.0–1.6MHz), with no external Schottky diode or inductor required.

Key Specifications

Pinout & Package

MP1519DQ-LF-Z is housed in a thermally enhanced 3mm × 3mm QFN16 package with exposed thermal pad connected internally to LEDC (Pin 8). The pad must be soldered to a dedicated PCB thermal plane for reliable power dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-channel white LED driver applications.

Compared with TPS61160DRVR and MAX1910ETE+, MP1519DQ-LF-Z uniquely combines 1x/1.5x/2x auto-switching, 2% matching, and QFN16 footprint - enabling longest battery runtime in sub-3.5V Li-Ion discharge profiles while minimizing board area.

Availability

MP1519DQ-LF-Z is available at Aetrix Electronics and suitable for cell phone backlighting, PDA display illumination, handheld medical device UIs, and portable barcode scanner displays requiring stable component supply across extended production lifecycles.

Supply support for MP1519DQ-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 power ICs, with core expertise in DC/DC conversion, LED drivers, and motor control.

The MP1519 belongs to MPS's white LED backlight driver product line, designed specifically for space-constrained portable devices requiring high-efficiency, inductorless, multi-LED solutions with precise current matching and wide input voltage tolerance.

FAQ

What is the minimum LED forward voltage supported by MP1519DQ-LF-Z?

The MP1519DQ-LF-Z supports LEDs with forward voltage up to 4V per string. Its 1x mode allows direct drive when V_BATT ≥ V_F, so minimum usable V_F is not specified - it regulates current regardless of V_F as long as total V_F ≤ charge pump output. Typical operation assumes ≥3.35V_F at 20mA per LED.

Can MP1519DQ-LF-Z drive fewer than four LEDs?

Yes. Pins LED1–LED4 are independent current sinks. Unused LED outputs (e.g., LED4) may be left unconnected without affecting regulation on active channels. LEDC remains the common cathode node for all connected LEDs, and the 4.7μF capacitor must still be placed.

How does the RADJ pin set LED current, and what resistor value gives 20mA?

RADJ connects to GND via R_SET; the internal 1.25V reference develops across it, yielding I_LED = 31.25 / R_SET (R_SET in kΩ). For 20mA, R_SET = 31.25 / 20 = 1.5625kΩ - a standard 1.54kΩ resistor achieves 20.3mA, matching the datasheet typical value.

Is the exposed thermal pad on MP1519DQ-LF-Z electrically connected, and how should it be handled?

Yes - the exposed pad is internally connected to LEDC (Pin 8), not GND. It must be soldered to a dedicated PCB copper pour tied only to LEDC and its 4.7μF bypass capacitor. Connecting it to system GND creates a short and will damage the IC.

What happens during EN-driven PWM dimming, and what frequency range is supported?

Each EN high pulse triggers full startup - including open-LED check and mode reselection. EN low for ≥30μs forces true shutdown (<1μA). Supported PWM frequency is 50Hz–50kHz; below 50Hz causes visible flicker, above 50kHz degrades dimming linearity due to fixed startup time (~100μs).

Does MP1519DQ-LF-Z include overtemperature protection?

No thermal shutdown circuit is documented in the datasheet. Protection relies on layout: θ_JA = 60°C/W and maximum junction temperature of 150°C imply safe operation up to ~180mA I_BATT with ≤30°C ambient rise - achieved via proper LEDC pad soldering and minimal trace resistance.

Can MP1519DQ-LF-Z operate with mismatched LED forward voltages?

Yes. Each channel regulates current independently using its own current-source architecture. Differences in V_F across LEDs cause no cross-talk or regulation error - only the common LEDC node voltage rises to accommodate the highest-V_F string.