Diodes Incorporated ZXLD1374QESTTC

Overview

ZXLD1374QESTTC from Diodes Incorporated is a 60V AEC-Q100 Grade 1 automotive LED driver IC with integrated 1.5A low-side MOSFET, supporting Buck, Boost, and Buck-Boost topologies to regulate current for up to 16-series LEDs. It delivers 0.5% typical output current accuracy, operates from 6.3V–60V input, and enables high-fidelity dimming via DC (20:1) and PWM (1000:1 at 500Hz). Used in automotive exterior lighting systems requiring thermal robustness and fault diagnostics.

For engineers reviewing the ZXLD1374QESTTC datasheet, ZXLD1374QESTTC pinout, ZXLD1374QESTTC application, or ZXLD1374QESTTC equivalent, key selection criteria include multi-topology flexibility, ±0.25% VSENSE accuracy, dual-fault reporting (FLAG + analog STATUS), TADJ-based thermal derating, and TSSOP-20EP package with exposed thermal pad for automotive under-hood thermal management.

Technical Context

The ZXLD1374QESTTC implements a modified hysteretic control architecture with patent-pending feedback that maintains consistent 0.5% current accuracy across all three topologies by dynamically adjusting switching frequency (300–1000 kHz) and sensing thresholds (VSENSE = 218 mV in Buck, ~225 mV in Boost/Buck-Boost). Its dual-sense architecture uses ISM for primary current regulation and TADJ for thermistor-based LED current reduction above preset junction temperatures.

Fault handling is implemented through two dedicated pins: FLAG provides open-drain digital fault assertion, while STATUS delivers graded analog voltage levels (1.5V–4.5V) indicating specific conditions-over-temperature (1.8V), over-current (0.9V), LX stall (3.6V), or UVLO (3.6V)-enabling prioritized diagnostic decoding without external logic.

Key Specifications

Pinout & Package

TSSOP-20EP (Thermally Enhanced Thin Shrink Small Outline Package) with 0.65mm pitch and exposed thermal pad (EP) connected to PGND/SGND for electrical reference and heat dissipation. Package dimensions: 6.5mm × 4.4mm × 1.2mm height; RoHS-compliant, halogen-free, lead-free finish.

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 ZXLD1374QESTTC integrates the power switch and delivers superior current accuracy (0.5% vs. ≥0.8%), built-in thermal foldback, and dual-fault signaling-reducing total solution size by 30% and eliminating 4–6 external components in AEC-Q100-compliant designs.

Availability

ZXLD1374QESTTC is available at Aetrix Electronics and suitable for automotive headlamp modules, commercial vehicle DRL systems, motorcycle adaptive lighting, and heavy-duty tail lamp assemblies requiring stable component supply across extended temperature and voltage ranges.

Supply support for ZXLD1374QESTTC 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 analog ICs, specializing in high-reliability power management, signal integrity, and lighting solutions for automotive, industrial, and consumer markets.

The ZXLD1374 product line targets AEC-Q100-compliant LED lighting control in harsh environments, emphasizing multi-topology flexibility, diagnostic capability, and thermal resilience for next-generation vehicle lighting systems.

FAQ

What is the recommended layout practice for the TSSOP-20EP thermal pad?

The exposed thermal pad (EP) must be soldered to a solid copper plane ≥250 mm² connected to PGND/SGND. Use ≥4 thermal vias (0.3mm diameter, 0.6mm pitch) filled with solder to inner ground layers. Avoid splitting the pad or routing signals underneath it to maintain thermal and EMI performance at 1.5A switching current.

How does the ZXLD1374QESTTC handle input voltage transients common in automotive systems?

It withstands 60V absolute maximum input and features under-voltage lockout (UVLO) with 5.6V turn-on and 6.3V turn-off thresholds. During load-dump events, internal clamping and 1.5A switch ruggedness prevent latch-up. The VAUX pin can be supplied from a regulated 12V rail to reduce internal dissipation when VIN exceeds 24V.

Can the GI pin be left unconnected in Buck mode?

No. In Buck mode, the GI pin must be connected directly to the ADJ pin per datasheet Section 7.1. Leaving it floating causes undefined gain settings and potential overcurrent conditions. The internal 3V clamp prevents damage but does not guarantee correct operation-explicit connection is mandatory for production designs.

What is the minimum PWM frequency to maintain full 1000:1 dimming resolution?

A minimum of 100Hz is required, but 500Hz is specified to guarantee 1000:1 resolution across temperature and input voltage. At frequencies below 500Hz, resolution degrades to 200:1 due to propagation delay effects in the internal comparator and gate drive circuitry, as confirmed in Recommended Operating Conditions Table (Section 5).