Monolithic Power Systems Inc. MPQ3386DR-LF-Z

Overview

MPQ3386DR-LF-Z 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 output from 4.5–25V input, regulates 20mA per string with ±3% matching accuracy, features selectable 1.25MHz/625kHz switching frequency, and supports PWM/DC-input dimming for automotive LCD backlighting.

For engineers reviewing the MPQ3386DR-LF-Z datasheet, MPQ3386DR-LF-Z pinout, MPQ3386DR-LF-Z application, or MPQ3386DR-LF-Z equivalent, this page provides verified technical context, real-world dimming implementation details, thermal shutdown behavior, OVP programming methodology, and validated alternative part comparisons for backlight system design.

Technical Context

The MPQ3386DR-LF-Z 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 dual SW pins (SW1/SW2) share a 0.3Ω typical R_DS(ON) MOSFET switch rated for 2.5A peak current and 50V swing.

Dimming is implemented via four modes: external PWM on PWMI, DC voltage on PWMO (0.2–1.2V), internal DPWM with FSET capacitor programming (100Hz–2kHz), or direct PWM with polarity options. Protection includes programmable OVP (1.23V threshold at OVP pin), open/short LED detection (175mV UVLO / 5.5V OV thresholds), and thermal shutdown at 150°C.

Key Specifications

Pinout & Package

MPQ3386DR-LF-Z uses a QFN-24 (4mm × 4mm) package with exposed thermal pad. Pin 1 identifier is marked in top-left corner; PGND1 and PGND2 must be shorted externally; SW1 and SW2 are internally independent but require external shorting for single-inductor operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ3386DR-LF-Z, MPQ3386GQ-AEC1-P offers identical performance with improved manufacturability, while LM3409QMY/NOPB demands significant redesign to achieve comparable 6-string control, protection, and thermal management.

Availability

MPQ3386DR-LF-Z is available at Aetrix Electronics and suitable for automotive instrument clusters, infotainment displays, and industrial panel PCs requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for MPQ3386DR-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ3386 belongs to MPS's automotive-grade LED driver product line, engineered specifically for high-reliability LCD backlighting in vehicles where thermal resilience, current matching, and functional safety are critical.

FAQ

What is the minimum recommended current-setting resistor value for MPQ3386DR-LF-Z?

The ISET pin requires a resistor tied from pin 11 to GND to set LED current using I_LED = 1.21V / R_SET. For maximum current of 33mA (per string), R_SET = 1.21V / 33mA ≈ 36.7kΩ. The datasheet specifies 40.2kΩ as the minimum standard value yielding 30mA, ensuring safe operation within SOA limits and thermal derating at 125°C.

How does the MPQ3386DR-LF-Z handle open LED string faults?

When an LED string opens, its corresponding LEDX pin voltage drops below 175mV. The IC detects this UVLO condition, marks off the faulty string, and continues regulating remaining strings using the highest-voltage string as reference. If all strings open, the boost converter shuts down after OVP threshold violation (~48–102mV at OVP pin).

Can MPQ3386DR-LF-Z operate with input voltage below 5.5V?

Yes - when VIN < 5.5V, the internal 5V LDO cannot regulate. In that case, VCC must be externally supplied with a stable 5V source, and VIN and VCC should be tied together. This bypasses the LDO while powering internal circuitry and gate drivers, maintaining full functionality including dimming and protection.

What is the purpose of the dual SW1/SW2 pins?

SW1 and SW2 are independent drain terminals of two internal power MOSFETs. They are intended for paralleled operation to reduce conduction loss and thermal stress. External shorting is mandatory per datasheet; doing so effectively doubles the current handling capacity and lowers R_DS(ON) impact on efficiency and thermal design.

Is the FSET capacitor value critical for DPWM frequency accuracy?

Yes - DPWM frequency follows f_DPWM = 3.5µF / C_FSET, with tolerance dominated by capacitor accuracy and temperature drift. For 1.6kHz target, C_FSET = 3.5µF / 1.6kHz ≈ 2.19nF; using a 2.2nF ±5% X7R ceramic yields 1.2–1.6kHz range, meeting typical backlight dimming requirements without trimming.

Does MPQ3386DR-LF-Z support daisy-chained communication or I²C configuration?

No - MPQ3386DR-LF-Z is an analog-controlled LED driver with no digital interface. All configuration (frequency, dimming, OVP) is performed via passive components (resistors, capacitors) and logic-level signals (EN, PWMI, PWMO). It does not include I²C, SPI, or SMBus interfaces.

What is the maximum allowable continuous power dissipation at 85°C ambient?

Using θ_JA = 42°C/W and T_J(MAX) = 150°C: P_D(MAX) = (150°C − 85°C) / 42°C/W ≈ 1.55W. This assumes proper PCB copper area (JESD51-7 4-layer board); actual dissipation must stay below this limit to avoid thermal shutdown, especially at high V_IN/V_OUT differentials.