Diodes Incorporated ZXGD3103N8TC

Overview

ZXGD3103N8TC from Diodes Incorporated is a synchronous MOSFET controller designed to replace body diodes in flyback and resonant DC-DC converters. It features differential sensing of MOSFET drain-source voltage, proportional gate drive (VG = 9.3–9.5 V at VD ≤ −200 mV), 15 ns turn-off propagation delay, 180 V drain voltage rating, and operation up to 250 kHz in DCM/CrCM/CCM modes - enabling high-efficiency secondary-side rectification in AC/DC adaptors and telecom PSUs.

For engineers reviewing the ZXGD3103N8TC datasheet, ZXGD3103N8TC pinout, ZXGD3103N8TC application, or ZXGD3103N8TC equivalent, key selection criteria include detector threshold (~10 mV), dual gate drive capability (2.5 A source / 6 A sink), SO-8 package thermal performance (RθJA = 159–255 °C/W), and compatibility with low-RDS(ON) MOSFETs in high-frequency offline power supplies.

Technical Context

The ZXGD3103N8TC implements a high-speed differential amplifier detector that monitors reverse VDS across an external MOSFET and triggers gate drive only when body diode conduction begins. Its output stage delivers asymmetric current drive: GATEH sources up to 2.5 A for fast turn-on, while GATEL sinks up to 6 A for rapid turn-off with 20 ns total fall time in DCM.

Operation relies on two external bias resistors (RBIAS, RREF) to set detection sensitivity and reference level, enabling stable ~10 mV threshold across temperature (−40°C to +150°C). The controller dynamically scales gate voltage proportionally to VDS during conduction, minimizing body diode time and optimizing efficiency without requiring PWM timing synchronization.

Key Specifications

Pinout & Package

Package: SO-8, surface-mount, lead-free, RoHS-compliant, moisture sensitivity level 1. Thermal resistance ranges from 159 °C/W (with 15 mm × 15 mm copper pads) to 255 °C/W (minimum FR-4 layout).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6908DJ-LF-Z and SRK2001TR, the ZXGD3103N8TC uniquely supports 180 V drain sensing, proportional gate drive for dynamic R_DS(ON) optimization, and sub-20 ns turn-off - making it the only option qualified for high-efficiency, high-voltage, high-frequency resonant converters in telecom and industrial lighting.

Availability

ZXGD3103N8TC is available at Aetrix Electronics and suitable for AC/DC adaptors, telecom PSUs, LED TV power supplies, and street lighting drivers requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for ZXGD3103N8TC 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-performance power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The ZXGD3103N8TC belongs to Diodes' synchronous rectification controller product line, engineered specifically to replace Schottky diodes in high-efficiency offline power converters - targeting >90% efficiency, reduced thermal stress, and simplified thermal design in space-constrained applications.

FAQ

What is the minimum recommended PCB layout practice for ZXGD3103N8TC's DRAIN pin?

The DRAIN pin must connect directly to the MOSFET drain with a PCB trace ≤10 mm in length to prevent parasitic inductance from causing false turn-off events. Use short, wide copper pours and avoid vias between DRAIN and MOSFET; place the IC adjacent to the MOSFET with GND plane underneath for low-inductance return path.

How does the ZXGD3103N8TC achieve proportional gate drive without external feedback?

It uses an internal differential amplifier that compares DRAIN-to-GND voltage against a reference derived from R_REF/R_BIAS. The resulting error signal directly controls GATEH/GATEL output amplitude - so VG rises linearly as |V_DS| increases, ensuring optimal MOSFET enhancement without closed-loop sensing.

Can ZXGD3103N8TC operate with a 5 V V_CC supply?

Yes - the device functions across 5–15 V V_CC. At 5 V, use RBIAS = 1.6 kΩ and RREF = 2.0 kΩ per Table 1 to maintain ~10 mV detection threshold. Gate drive voltage scales down accordingly (VG ≈ 4.5–4.7 V), sufficient for logic-level MOSFETs with V_GS(th) ≤ 2.5 V.

Why does ZXGD3103N8TC specify separate GATEH and GATEL pins instead of a single gate driver?

Separate sourcing (GATEH) and sinking (GATEL) paths enable independent optimization: GATEH delivers high peak current for fast MOSFET turn-on, while GATEL provides stronger sink capability (6 A vs. 2.5 A source) to overcome Miller plateau and ensure sub-20 ns turn-off - essential for zero-current switching in CrCM/CCM.