Diodes Incorporated ZXLD1366QDACTC

Overview

ZXLD1366QDACTC from Diodes Incorporated is an AEC-Q100 Grade 1 qualified continuous-mode inductive step-down LED driver IC, designed for high-accuracy constant-current control of single or series-connected LEDs in automotive and industrial lighting. It operates from 6V to 60V input, delivers up to 1A output current with ±0.8% accuracy, uses high-side current sensing via external resistor (RS), and supports PWM dimming up to 1000:1 resolution. Used in emergency lighting and refrigeration LED systems where thermal robustness and wide VIN range are critical.

For engineers reviewing the ZXLD1366QDACTC datasheet, ZXLD1366QDACTC pinout, ZXLD1366QDACTC application, or ZXLD1366QDACTC equivalent, key selection criteria include its 60V max input rating, 1A switch current capability, V-DFN3030-6 thermal performance (θJA = 44°C/W), AEC-Q100 qualification, and ADJ pin-based DC/PWM brightness control with 0.2V shutdown threshold.

Technical Context

The ZXLD1366QDACTC implements a self-oscillating buck converter architecture with internal NMOS switch (RLX = 0.50–0.75Ω), using high-side current sensing referenced to VIN via the ISENSE pin. Its comparator-driven control loop maintains average LED current by regulating LX duty cycle based on VSENSE voltage across RS, with hysteresis set to ±15% of VADJ.

Operation is governed by the ADJ pin: floating at 1.25V sets nominal current (IOUTnom = 0.2V/RS); DC voltage (0.3–2.5V) scales output linearly; PWM applied here enables high-resolution dimming; ≤0.2V forces shutdown with 65µA quiescent current. Soft-start is externally programmable via capacitor from ADJ to GND.

Key Specifications

Pinout & Package

V-DFN3030-6 package: 3.0mm × 3.0mm × 0.8mm body, thermally enhanced exposed pad (EP) connected to substrate and requiring PCB thermal land for θJA = 44°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL8862Q-7 and LM3409QMY/NOPB, the ZXLD1366QDACTC uniquely combines AEC-Q100 Grade 1, 60V input, single-pin dimming, and ±0.8% accuracy in a thermally efficient 3×3mm DFN-making it optimal for space- and reliability-constrained automotive and industrial LED systems.

Availability

ZXLD1366QDACTC is available at Aetrix Electronics and suitable for emergency lighting, refrigeration LED modules, and automotive backup lamps requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for ZXLD1366QDACTC 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and ICs, specializing in high-reliability power management, signal integrity, and lighting solutions for automotive and industrial markets.

The ZXLD1366 belongs to Diodes' AEC-Q100-qualified LED driver product line, engineered specifically for thermally demanding, safety-critical automotive exterior and interior lighting applications.

FAQ

What is the minimum sense resistor value for 1A output?

The minimum RS value is 0.2Ω, which sets IOUTnom = 0.2V / 0.2Ω = 1A when the ADJ pin is floating at 1.25V. Using RS < 0.2Ω risks exceeding the 1A maximum switch current rating and violates the absolute maximum condition specified in the datasheet.

Can ZXLD1366QDACTC operate with input voltage below 6V?

No-operation below 6V is outside the recommended operating conditions. The internal regulator requires ≥4.85V to start, and the device may not sustain regulation or deliver rated current below 6V, risking instability or premature shutdown per the datasheet's VIN min specification.

How does the ADJ pin achieve 1000:1 PWM dimming?

The ADJ pin accepts low-frequency PWM (≤300Hz) with amplitude matching VREF (1.25V). The internal low-pass filter converts PWM duty cycle into an effective DC voltage that modulates the VSENSE threshold, enabling precise current scaling from 0.1% to 100% of nominal output-achieving 1000:1 ratio.

Is the exposed pad (EP) required to be connected to ground?

Yes-the EP must be soldered to the PCB's power ground plane to achieve the specified θJA = 44°C/W. While it is not a current-carrying path, omitting EP connection degrades thermal performance by >30°C/W, risking thermal shutdown or reduced lifetime at 1A load.