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url: /en/docs/xt-c-485-hia-v3_5/index.md
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# RS485 Isolated Surge-Protected Castellated SMD Module

**Model**: XT-C-485-HIA-V3/5

3.0–5.5 V input RS-485 module with isolation and a surge gas discharge tube, **usable as SMD or through-hole** (castellated half-holes + full plated through-holes).

## Overview

`XT-C-485-HIA-V3/5` is an industrial isolated RS-485 half-duplex transceiver module, 90 × 20 mm. At its core is the **TDA51S485HC** single-chip isolated transceiver — the isolated supply and the isolated signal path are integrated in one SOIC-16W package, so no external isolated DC-DC module is needed. Beyond the isolated transceiver sits a four-stage protection chain: **gas discharge tube + TVS + current-limiting resistors + common-mode choke**.

**Both mounting styles work**: every pad carries a **castellated half-hole** at the board edge *and* a **full plated through-hole** —

* To surface-mount: solder the module **flat** onto your main board like an ordinary SMD part
* To through-hole mount: insert a **2.54 mm pin header** or a **5.08 mm terminal** and solder it

## Contents

* [Getting Started](./getting-started.md)
* [Specifications](./specs.md)
* [Pinout](./pinout.md)
* [Schematic](./schematic.md)

> The full parameter table, protection chain and component choices are on the [product page](/en/products/xt-c-485-hia-v3_5/).