Diodes Incorporated ZXGD3101N8TC

Overview

ZXGD3101N8TC from Diodes Incorporated is a synchronous rectifier controller IC designed to replace Schottky diodes in high-efficiency AC-DC and DC-DC power converters. It drives external N-channel MOSFETs as ideal diodes, featuring 15 ns turn-off propagation delay, 20 ns turn-off time, and operation across DCM/CrCM/CCM modes. Used in flyback and LLC topologies for LCD monitors, server PSUs, and street lighting.

For engineers reviewing the ZXGD3101N8TC datasheet, ZXGD3101N8TC pinout, ZXGD3101N8TC application, or ZXGD3101N8TC equivalent, key selection criteria include gate drive sink/source capability (7 A sink / 4 A source), drain voltage tolerance (−3 V to +180 V), differential detection threshold (−45 mV typ), SO-8 package thermal resistance (R_θJA = 255 °C/W), and Energy Star V2.0 compliance.

Technical Context

The ZXGD3101N8TC integrates a high-speed differential amplifier detector and dual-output gate driver. Its detector senses MOSFET drain-source reverse voltage with sub-50 mV turn-on threshold and delivers gate voltage proportional to V_DS, enabling adaptive conduction control. The GATEH/GATEL outputs provide independent sourcing and sinking paths for precise MOSFET switching timing.

It supports three conduction modes-Discontinuous, Critical, and Continuous-via dynamic threshold response and fast propagation (15 ns off, 525 ns on). Bias and reference current paths (I_REF = 25 mA, I_BIAS = 100 mA) are externally resistor-configured to set offset voltage (~20 mV) and ensure stable zero-current detection during turn-off.

Key Specifications

Pinout & Package

Package: SO-8 (Surface-mount, 1.27 mm pitch, 4.9 mm × 6.0 mm body). Thermal pad not present; junction-to-ambient rating assumes standard FR4 board with minimal copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous rectifier controller applications.

Compared with MP6908GJ-Z and UCC24612-2QDRQ1, the ZXGD3101N8TC offers wider drain voltage range (−3 V to +180 V), externally adjustable threshold via R_REF/R_BIAS, and higher sink current (7 A), making it optimal for high-reliability industrial and lighting applications where flexibility and ruggedness outweigh integration benefits.

Availability

ZXGD3101N8TC is available at Aetrix Electronics and suitable for flyback adaptors, server PSUs, and LLC-based street lighting drivers requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for production ramp-up.

Supply support for ZXGD3101N8TC 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, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The ZXGD series targets high-efficiency power conversion, specifically addressing synchronous rectification challenges in AC-DC and isolated DC-DC topologies where precision zero-current detection and robust gate drive are critical.

FAQ

What is the recommended external resistor value for R_REF when V_CC = 12 V?

R_REF should be selected to deliver ~3 mA into the REF pin. Given the REF pin voltage is ~0.7 V above GND, R_REF = (12 V − 0.7 V) / 0.003 A = 3.77 kΩ. Standard E24 value 3.9 kΩ is recommended, yielding 2.89 mA - within acceptable tolerance per datasheet Note 8.

Can ZXGD3101N8TC drive high-side MOSFETs in forward converter topologies?

Yes - Figure 3 in the datasheet explicitly shows high-side configuration. The DRAIN pin connects to the MOSFET drain, GND to source, and GATEH/GATEL drive the gate. Layout must minimize ground loop inductance, and V_CC must be referenced to source potential via isolated bias winding or bootstrap circuit.

Does the device require a minimum load on V_CC to maintain regulation?

No - ZXGD3101N8TC has no internal regulator; V_CC is directly supplied to internal circuitry. Operating current ranges from 3 mA (VD ≤ −200 mV) to 8 mA (VD ≥ 0 V), so no minimum load is needed. However, a 100 nF X7R capacitor between V_CC and GND is mandatory to absorb gate drive transient currents.

How does the device handle negative V_DS undershoot during fast turn-off?

The DRAIN pin is rated for −3 V minimum, and the detector's input stage clamps negative excursions beyond this using internal protection diodes. For systems with >3 V undershoot (e.g., due to layout inductance), an external 3.3 V TVS diode from DRAIN to GND is recommended per AN54 layout guidelines.