Diodes Incorporated ZXLD1371QESTTC

Overview

ZXLD1371QESTTC from Diodes Incorporated is a high-accuracy, AEC-Q100 qualified LED driver controller IC for buck, boost, and buck-boost topologies. It drives external NMOS FETs to regulate constant current up to 1 A across 1–16 LEDs, supports 5–60 V input, achieves ±0.25% VSENSE accuracy, and enables 1000:1 PWM dimming at 100–500 Hz in automotive lighting systems.

For engineers reviewing the ZXLD1371QESTTC datasheet, ZXLD1371QESTTC pinout, ZXLD1371QESTTC application, or ZXLD1371QESTTC equivalent, key selection criteria include its 300–1000 kHz programmable switching frequency, thermal foldback via TADJ, dual dimming (DC + PWM), fault reporting via STATUS/FLAG pins, and TSSOP-16EP package with exposed paddle for thermal management.

Technical Context

The ZXLD1371 uses a modified hysteretic control scheme with internal 1.25 V reference and fixed 218 mV (buck) / variable 225 mV (boost/buck-boost) current-sense threshold. Its GI pin selects topology by setting gain ratio (0.20–0.50), while SHP pin connects a 330 pF capacitor for loop compensation.

Thermal protection operates via TADJ pin with 560–690 mV upper threshold and 380–500 mV lower threshold; STATUS pin provides analog voltage-coded fault reporting (e.g., 0.9 V = overcurrent, 1.8 V = overtemperature); FLAG is open-drain for digital fault indication.

Key Specifications

Pinout & Package

TSSOP-16EP package with exposed thermal pad (EP) connected to PGND for electrical and thermal management; 16-pin layout optimized for high-current LED driver layout with separated signal (SGND) and power (PGND) grounds.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL8862Q-13 and LM3409QMY/NOPB, the ZXLD1371QESTTC delivers superior current accuracy (±0.25% vs. ≥1.5%), integrated thermal foldback (no MCU dependency), and analog-coded fault reporting-reducing system-level validation effort in automotive lighting designs.

Availability

ZXLD1371QESTTC is available at Aetrix Electronics and suitable for automotive headlamps, commercial signage, truck tail lights, and industrial control panels requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for ZXLD1371QESTTC 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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, and consumer markets.

The ZXLD1371 belongs to Diodes' AEC-Q100 qualified LED driver controller product line, designed specifically for high-reliability automotive exterior lighting applications requiring precision current regulation and robust fault handling.

FAQ

What is the minimum input voltage required for reliable startup of the ZXLD1371QESTTC?

The ZXLD1371QESTTC starts up reliably above 5.4 V due to its under-voltage lockout (UVLO) threshold of 4.9 V (rising). While it can operate down to 5.0 V after startup, performance-including output current accuracy and switching frequency stability-is guaranteed only above 8.0 V per the recommended operating conditions in DS35436 Rev. 1.

How does the GI pin configure boost versus buck-boost topology?

The GI pin sets gain ratio (VGI/VADJ) between 0.20 and 0.50 using a resistive divider from ADJ to SGND. A ratio of 0.23 configures boost mode; 0.35–0.50 selects buck-boost. In buck mode, GI is tied directly to ADJ. This ratio adjusts internal feedback loop gain to compensate for duty-cycle-dependent sense voltage variation in non-buck topologies.

Can the ZXLD1371QESTTC drive more than one LED string simultaneously?

No-the ZXLD1371QESTTC regulates current through a single external sense resistor, supporting only one LED string per device. For multi-string applications, multiple ZXLD1371QESTTC units must be used with individual sense resistors and synchronized PWM inputs to avoid current imbalance and thermal runaway.

What is the purpose of the SHP pin and its required external component?

The SHP pin connects a 330 pF ±20% capacitor to ground to provide loop compensation for the hysteretic control architecture. This capacitor stabilizes the feedback response across input voltage, LED forward voltage, and temperature variations-ensuring consistent current regulation and preventing oscillation in all three topologies.