Diodes Incorporated ZXLD1371QEV2

Overview

ZXLD1371QEV2 from Diodes Incorporated is an evaluation board for the ZXLD1371 LED driver IC, implementing a Buck-Boost topology to drive up to 5 LEDs at 680mA from 5.4–30V DC input. It features PWM (inverted), ADJ (DC dimming), and TADJ (NTC thermal dimming) control inputs, plus VAUX, FLAG, STATUS, and LX monitoring points for real-time signal analysis during LED lighting design validation.

For engineers reviewing the ZXLD1371QEV2 datasheet, ZXLD1371QEV2 pinout, ZXLD1371QEV2 application, or ZXLD1371QEV2 equivalent, this board supports rapid prototyping of automotive interior lighting, industrial status indicators, and architectural accent lighting where wide-input-voltage LED regulation with multi-mode dimming is required.

Technical Context

The ZXLD1371QEV2 implements a synchronous Buck-Boost converter using the ZXLD1371Q TSSOP-16EP IC, Q1 (DMN6068LK3 N-MOSFET), D1 (PDS5100 freewheeling diode), and L1 (33µH inductor). Input voltage range is 5.4–30V; output current is fixed at 680mA with up to 5-series LEDs.

It integrates three independent dimming interfaces: inverted PWM (100–500Hz recommended), 0.125–1.25V analog ADJ input (R8 removal required), and TADJ for 10kΩ NTC-based thermal foldback (~70°C trip with R7 = 1.8kΩ). VAUX monitoring enables bootstrap circuit verification or external auxiliary supply injection.

Key Specifications

Availability

ZXLD1371QEV2 is available at Aetrix Electronics and suitable for automotive cabin lighting validation, industrial HMI backlighting, architectural LED strip testing, and portable battery-powered illumination systems requiring stable component supply and fast-turn evaluation support.

Supply support for ZXLD1371QEV2 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 integrated circuits, specializing in power management, signal integrity, and lighting solutions for industrial, automotive, and consumer markets.

The ZXLD1371QEV2 belongs to Diodes' LED driver evaluation platform family, designed specifically to accelerate development of high-efficiency, thermally robust, multi-dimming-mode LED lighting systems using their proprietary Buck-Boost controller architecture.

FAQ

What is the purpose of the inverted PWM̅̅̅̅̅̅̅̅ input on the ZXLD1371QEV2?

The inverted PWM input allows wire-OR connection with the overvoltage protection circuit on the ZXLD1371 IC. A logic-low signal enables full LED brightness, while logic-high reduces current. This inversion simplifies integration with standard microcontroller GPIOs that may lack active-low PWM drivers, and ensures fail-safe shutdown if the protection circuit asserts.

Can the ZXLD1371QEV2 drive more than 5 LEDs?

No - the board is configured for a maximum of 5-series LEDs based on its component selection (L1 = 33µH, D1 = PDS5100, Q1 = DMN6068LK3) and layout constraints. Driving more LEDs would exceed the LX node voltage rating (~50V max), risk exceeding the MOSFET's 60V V_DSS, and compromise thermal stability without redesign of inductor, diode, and current-sense network.

How do I enable DC dimming using the ADJ input?

To enable DC dimming, remove resistor R8 (0Ω jumper) from the ADJ path. Then apply a 0.125–1.25V analog voltage to the ADJ test point relative to GND: 0.125V sets minimum LED current (~10% of 680mA), and 1.25V sets full 680mA output. The linear relationship is internally calibrated per the ZXLD1371 IC's reference design.

Is the VAUX monitoring point intended only for measurement?

No - VAUX serves dual purpose: it provides access to the internal auxiliary supply node for oscilloscope probing, and can accept an external 5–7V source when R3 and R4 are removed. This bypasses the internal bootstrap circuit (D2 + R4), enabling reliable operation at low input voltages (5–8V) where bootstrapping may be unstable due to insufficient gate drive margin.