Diodes Incorporated ZXCT1032N8TA

Overview

ZXCT1032N8TA from Zetex Semiconductors is a high-side inrush current controller and electronic fuse IC that drives external PMOS or PNP transistors to limit startup surge and provide over-current protection. It integrates a high-accuracy current monitor, linear soft-start ramp control (set by CT capacitor), re-try inhibit timer, and active-low fault flag. Operates from 9.5V to 21V supply, supports trip currents up to 1A (with RSENSE = 0.2Ω), and delivers precise 2.1V internal ISET reference.

For engineers reviewing the ZXCT1032N8TA datasheet, ZXCT1032N8TA pinout, ZXCT1032N8TA application, or ZXCT1032N8TA equivalent, key selection criteria include its user-adjustable trip threshold (via ISET voltage or PWM), CT-timed soft-start and auto-retry behavior, SO8 package compatibility, and high-side sensing capability for hot-swap and PoE feed protection.

Technical Context

The ZXCT1032N8TA implements a three-mode control architecture: linear soft-start (CT-charging phase with controlled MOSFET turn-on), over-current detection (transparent operation with full MOSFET enhancement), and latched over-current disconnect (Drive high, Flag low, CT discharge via 3.3µA sink). Its current sense loop includes a +150mV output offset, requiring VSENSE = (VISET − 150mV)/10 for trip calculation.

It uses an internal 2.1V ±0.1V ISET reference (50kΩ source impedance) when left open, supports dynamic VISET adjustment (1V–2.5V), and features temperature-stable trip voltage (95 ppm/°C TC). CT charge current is 200µA (typ), discharge current is 3.3µA (typ), enabling repeatable timing for fault recovery cycles.

Key Specifications

Pinout & Package

ZXCT1032N8TA is housed in an SO8 surface-mount package (4.80–5.00mm × 3.80–4.00mm, 1.27mm pitch), rated for −40°C to +85°C ambient operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side inrush and electronic fuse applications.

Compared with MAX4210DESA+ and LM5069MMX-2, the ZXCT1032N8TA uniquely combines internal 2.1V reference, CT-timed soft-start, and auto-retry in SO8 - making it optimal for cost-sensitive 12V/24V hot-swap and electronic fuse designs where minimal external components and predictable timing are critical.

Availability

ZXCT1032N8TA is available at Aetrix Electronics and suitable for electronic fuse implementation, hot-swap controller design, and short-circuit protected supply feed applications requiring stable component supply and long-term industrial availability.

Supply support for ZXCT1032N8TA 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

Zetex Semiconductors plc was a UK-based analog and power management IC manufacturer, acquired by Diodes Incorporated in 2008; known for precision current sensing and high-reliability interface products.

The ZXCT series was designed specifically for high-side current monitoring and electronic fuse functionality in industrial and telecom power systems - emphasizing simplicity, thermal robustness, and minimal external component count.

FAQ

What is the maximum allowable VSENSE differential voltage for ZXCT1032N8TA?

The absolute maximum differential voltage between IN+ and IN− is 500mV. However, the functional trip range is limited to 185–205mV at VISET = 2.1V. Exceeding 500mV risks permanent damage to the internal current sense amplifier, and operation above 205mV without fault assertion indicates incorrect RSENSE or VISET configuration.

Can ISET be driven directly by a microcontroller GPIO pin?

Yes - ISET accepts DC voltage or PWM signals, but the GPIO must drive into the 50kΩ internal source impedance. For reliable operation, use a GPIO capable of sourcing/sinking ≥100µA at the target VISET voltage (1V–2.5V); avoid high-impedance outputs or open-drain configurations without pull-up/down.

How does the 150mV output offset affect trip point calculation?

The current monitor adds a fixed +150mV offset to its output. Therefore, the actual sense voltage at trip is VSENSE = (VISET − 150mV)/10. For example, with VISET = 2.1V, VSENSE = 195mV - meaning RSENSE × ITRIP = 195mV. This offset ensures zero-current disable when VISET < 100mV.

Is ZXCT1032N8TA RoHS compliant and lead-free?

Yes - per Zetex's green compliance statement in the datasheet, all components including ZXCT1032N8TA meet EU RoHS Directive 2011/65/EU requirements and are lead-free, halogen-free, and compliant with WEEE and ELV directives.