{"product_id":"a-four-channel-rs-422-differential-line-receiver-and-transmitter-module","title":"A Four-Channel RS-422 Differential Line Receiver and Transmitter Module","description":"\u003cp\u003e\u003cspan\u003eThis Quadruple Differential Line Driver module provides four independent differential output channels for driving balanced transmission lines in industrial and embedded applications. Built around the \u003c\/span\u003e\u003ca href=\"https:\/\/www.ti.com\/product\/AM26LS31\" target=\"_blank\"\u003eTexas Instruments AM26LS31\u003c\/a\u003e\u003cspan\u003e IC in a DIP-16 package, the module meets TIA\/EIA-422-B and ITU standards. It delivers high-current 3-state outputs capable of driving twisted-pair or parallel-wire transmission paths. In my next project, I will show you how to build the complementary four-channel RS-422 differential line receiver.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eAn onboard LM7805C regulator accepts 7–18V DC input and supplies a stable 5V rail to the driver IC. The assembled module is shown in Figure 1.\u003c\/p\u003e\n\u003cp\u003eAll four driver channels share a common enable circuit with both active-high (G) and active-low (!G) enable inputs, brought out to solder jumpers on the back of the PCB. This flexibility allows the module interface to communicate directly with microcontrollers or PLCs regardless of the enable polarity.\u003c\/p\u003e\n\u003cp\u003eScrew terminals (5.08 mm pitch) connect the four differential output pairs to a transmission cable, while an 8-pin header provides the digital data inputs at 2.54 mm pitch for easy breadboard or jumper-wire connection.\u003c\/p\u003e\n\u003cp\u003eWhen power is removed, the 3-state output stage automatically places all outputs in a high-impedance condition, preventing bus loading in multi-drop configurations. The module targets applications including industrial encoder interfaces, fieldbus sensor transmitters, Modbus temperature controllers, and motor control systems where data integrity over cable runs is critical.\u003c\/p\u003e\n\u003ch3\u003eSpecs and Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSupply voltage: 7–18 VDC\u003c\/li\u003e\n\u003cli\u003e4-channel differential output (TIA\/EIA-422-B \/ ITU compliant)\u003c\/li\u003e\n\u003cli\u003eKey IC: AM26LS31 (DIP-16, Bi-CMOS)\u003c\/li\u003e\n\u003cli\u003e3-state outputs with high-impedance power-off condition\u003c\/li\u003e\n\u003cli\u003eActive-high (G) and active-low (!G) enable inputs via solder jumpers\u003c\/li\u003e\n\u003cli\u003eOnboard 5 V regulator: LM7805C (TO-220), with reverse-polarity diode protection\u003c\/li\u003e\n\u003cli\u003eOutput screw terminals: 5.08 mm pitch (CN1, CN4, CN5, CN7)\u003c\/li\u003e\n\u003cli\u003eDigital input header: 8-pin, 2.54 mm pitch (CN3)\u003c\/li\u003e\n\u003cli\u003ePower LED indicator\u003c\/li\u003e\n\u003cli\u003ePCB dimensions: 46.36 × 30.48 mm\u003c\/li\u003e\n\u003cli\u003eFour 3 mm mounting holes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis design is for a quadruple differential line receiver designed for balanced or unbalanced digital data transmission over RS-422 and RS-485 links. It accepts four independent differential input pairs and converts them to single-ended digital outputs suitable for direct connection to a microcontroller or bus-organized system. It also complements our previous project, a four-channel RS-422 differential line driver.\u003c\/p\u003e\n\u003cp\u003eThe fully assembled board is shown in Figure 1. All four receivers share a common enable function with both active-high and active-low control inputs, and the 3-state outputs allow safe multi-device bus sharing.\u003c\/p\u003e\n\u003ch3\u003eSpecs and Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePower input: 7 to 18 VDC\u003c\/li\u003e\n\u003cli\u003eOn-board 5 V regulation via LM7805\u003c\/li\u003e\n\u003cli\u003e±7 V common-mode range with ±200 mV sensitivity\u003c\/li\u003e\n\u003cli\u003eInput hysteresis: 60 mV typical\u003c\/li\u003e\n\u003cli\u003e3-state outputs — bus-compatible\u003c\/li\u003e\n\u003cli\u003eFail-safe: open inputs default to logic high\u003c\/li\u003e\n\u003cli\u003eCommon enable with active-high and active-low inputs (solder-jumper selectable)\u003c\/li\u003e\n\u003cli\u003eFour 120 Ω on-board termination resistors\u003c\/li\u003e\n\u003cli\u003eOn-board power LED\u003c\/li\u003e\n\u003cli\u003eScrew terminals for twisted-pair input cables (5.08 mm pitch)\u003c\/li\u003e\n\u003cli\u003e8-pin output header for microcontroller interfacing (2.54 mm pitch)\u003c\/li\u003e\n\u003cli\u003ePCB dimensions: 55.25 mm × 37.47 mm\u003c\/li\u003e\n\u003cli\u003eFour 3 mm mounting holes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"dotfry","offers":[{"title":"Default Title","offer_id":47246434631852,"sku":"B145","price":45.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/6436\/7532\/files\/B145.png?v=1789807884","url":"https:\/\/dotfry.com\/products\/a-four-channel-rs-422-differential-line-receiver-and-transmitter-module","provider":"dotfry","version":"1.0","type":"link"}