Monolithic Power Systems Inc. MPQ3386DR-LF-P

Overview

MPQ3386DR-LF-P from Monolithic Power Systems is a 6-channel, AEC-Q100 Grade 1 qualified white LED driver IC with integrated step-up converter and current-regulated outputs. It delivers up to 50V boost output from 4.5–25V input, regulates 20mA per string with ±3% matching accuracy, and supports selectable 1.25MHz/625kHz switching frequency - designed for automotive LCD backlighting in instrument clusters and center displays.

For engineers reviewing the MPQ3386DR-LF-P datasheet, MPQ3386DR-LF-P pinout, MPQ3386DR-LF-P application, or MPQ3386DR-LF-P equivalent, key selection criteria include its 600mV LED current-sense voltage (reducing conduction loss), dual dimming modes (external PWM and DC-input PWM), open/short LED fault protection, thermal shutdown at 150°C, and QFN-24 (4×4mm) package with exposed thermal pad.

Technical Context

The MPQ3386DR-LF-P integrates a fixed-frequency peak-current-mode boost controller with six matched open-drain current sinks. Its internal 5V LDO (VCC) powers gate drivers and logic, while the COMP pin enables loop compensation via external RC networks. The device uses a single feedback reference (600mV) across all strings and automatically selects the highest active LEDX voltage to regulate bus voltage.

It implements dual-level protection: OVP threshold set via resistor divider on the OVP pin (trip at 1.23V), and per-string fault detection - open strings identified by LEDX < 175mV, short strings by LEDX > 5.5V sustained >1.6ms. VFAULT drives an external PMOS for input-output isolation during fault conditions.

Key Specifications

Pinout & Package

MPQ3386DR-LF-P is housed in a thermally enhanced QFN-24 package (4mm × 4mm, 0.5mm pitch) with exposed thermal pad connected internally to GND. The package supports high-power dissipation (θ_JA = 42°C/W) and requires proper PCB copper pour under the pad for thermal reliability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 6-channel WLED driver applications.

Compared with MPQ3386DR-AEC1, the MPQ3386DR-LF-P offers identical electrical performance but omits AEC-Q100 certification documentation - making it ideal for cost-sensitive industrial or commercial backlighting. Versus LM3409QMY/NOPB, it delivers plug-and-play 6-string integration with lower layout risk and faster time-to-test, though less topology flexibility.

Availability

MPQ3386DR-LF-P is available at Aetrix Electronics and suitable for automotive instrument clusters, center-stack infotainment displays, and commercial vehicle digital dashboards requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MPQ3386DR-LF-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 power management ICs, with core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MPQ3386 belongs to MPS's automotive-grade LED driver product line, engineered specifically for AEC-Q100 compliance and high-reliability LCD backlighting in safety-critical vehicle interfaces.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MPQ3386DR-LF-P has an input UVLO rising threshold of 3.4V to 4.3V (typ. 3.9V) with 165mV hysteresis. For guaranteed startup under cold-crank conditions, VIN must exceed 4.5V - below this, the internal 5V LDO cannot power gate drivers, and the chip remains disabled even if EN is asserted.

Can MPQ3386DR-LF-P drive fewer than 6 LED strings?

Yes - unused LEDX pins (e.g., LED4–LED6) must be tied directly to VOUT, not left floating. This prevents false open-string detection and ensures the remaining active strings receive full current regulation. The device automatically adapts regulation to the highest-voltage active string.

How is over-voltage protection configured, and what happens when triggered?

OVP is set using a resistor divider from VOUT to the OVP pin, triggering shutdown when voltage at OVP reaches 1.23V. Upon trip, the boost switch disables, VFAULT pulls low to turn off the external PMOS, and the FAULT flag persists until power cycle or EN toggle - preventing automatic recovery during persistent overvoltage.

What is the purpose of the dual SW1/SW2 and PGND1/PGND2 pins?

SW1 and SW2 are paralleled internal MOSFET drains; PGND1 and PGND2 are separate high-current ground returns. This dual-pin layout reduces parasitic inductance in the high-di/dt boost loop, minimizing voltage spikes and EMI - critical for passing CISPR-25 Class 5 automotive EMC tests.

Does MPQ3386DR-LF-P support analog dimming?

No - it does not support true analog (linear) dimming. It supports only PWM-based methods: external logic PWM (PWMI), filtered PWM converted to DC (PWMO), or direct DC voltage input (0.2–1.2V on PWMO). All methods modulate LED current via duty-cycle control, not linear current reduction.

What is the maximum allowable LED string voltage drop per channel?

Each LEDX pin supports up to 50V relative to GND. With 600mV regulation voltage, the maximum forward voltage per string is VOUT – 0.6V. Since VOUT is rated to 50V, individual strings may have up to 49.4V total forward drop - sufficient for ≥15 white LEDs (3.2V avg.) in series.

Is thermal derating required above 85°C ambient?

Yes - the device is rated for TJ = −40°C to +125°C, but continuous power dissipation drops linearly above TA = 25°C due to θ_JA = 42°C/W. At 85°C ambient, max allowable power is (125−85)/42 ≈ 0.95W - requiring careful thermal pad soldering and PCB copper area to maintain safe junction temperature.