{"product_id":"adafruit-adg728-1-to-8-analog-matrix-switch-stemma-qt","title":"Adafruit ADG728 1-to-8 Analog Matrix Switch","description":"\u003cp\u003eAnalog switches are a solid state alternative to relays, when you want a smaller, lower-power technology that won't wear out mechanically. And, as the name implies, you can use the \u003cstrong\u003eAdafruit ADG728 1-to-8 Analog Matrix Switch\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eto connect between eight analog signals, much like a set of 8 mechanical switches. These chips tend to be tiny surface mount parts, so this breakout will let anyone use the ADG728 switch for signals up to 5V, without fiddly soldering.\u003c\/p\u003e\n\u003cp\u003eThe ADG728 uses I2C to select which of the 8 channels switches to turn on or off, to connect that channel to the single analog 'D' pin Note that unlike digital switches and multiplexers, these are not 'input' and 'output' because the signal is bidirectional. You could have the D signal be an input to 8 outputs, or the 8 inputs to one output.\u003c\/p\u003e\n\u003cp\u003eAlso, the ADG728 isn't really a 'selecting multiplexer',\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eits a matrix switch with 8 independent switches\u003c\/strong\u003e. That means that yes, you could treat it like an SP8T where you select which signal is routed to the D pin, you can also turn on multiple switches to 'merge' the signals together. \u003c\/p\u003e\n\u003cp\u003eUnlike a relay or mechanical switch, analog switches don't wear out, and the switch time is near instant, about 100nS. The ADG728 chip also guarantees break-before-make so the deselected switches will open before selected switches close.\u003c\/p\u003e\n\u003cp\u003eHowever, there's a few things to watch out for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe Vin power pin\u003c\/strong\u003e (the red wire if using a STEMMA QT cable) \u003cstrong\u003emust as high as the highest analog voltages you want to switch\u003c\/strong\u003e. That means if the analog signals are no more than 5VDC, the V+ pin must be higher than 5V. You cannot power this pin with 3.3V and switch 5V signals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt cannot switch signals below ground\u003c\/strong\u003e. No negative voltages can be applied to the Switch or D pins!\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnalog switches are for signals, not power! \u003c\/strong\u003eSince this is not a mechanical switch, the signals pass through circuitry that is not designed to source or sink current. This is great for analog signal voltages, and is not good for providing more than a few mA of current.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIn addition to the 8 switch S pins and the D pin that can be switched to, there's also two I2C address pins so you can change the default address from 0x4C up to 0x4F. There's also a reset pin if you want to immediately set all the switches to open.\u003c\/p\u003e\n\u003cp\u003eTo get you going fast, we spun up a custom-made PCB in the\u003ca href=\"\/en-us\/collections\/stemma-qt\" title=\"STEMMA QT form factor\" target=\"_blank\" rel=\"noopener\"\u003e \u003cstrong\u003eSTEMMA QT\u003c\/strong\u003e form factor\u003c\/a\u003e, making it easy to interface with. The \u003ca href=\"https:\/\/learn.adafruit.com\/introducing-adafruit-stemma-qt\/what-is-stemma-qt\"\u003eSTEMMA QT connectors\u003c\/a\u003e on either side are compatible with the \u003ca href=\"https:\/\/www.sparkfun.com\/qwiic\"\u003eSparkFun Qwiic\u003c\/a\u003e I2C connectors. This allows you to make solderless connections between your development board and the ADG or to chain it with a wide range of other sensors and accessories using a \u003ca href=\"\/en-us\/products\/jst-sh-cable-qwiic-stemma-qt-compatible\" target=\"_blank\" rel=\"noopener\"\u003e\u003cstrong\u003ecompatible cable\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eTechnical Details\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eADG728 Specifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eI2C Interface\u003c\/li\u003e\n\u003cli\u003e2.7 V to 5.5 V Single Supply\u003c\/li\u003e\n\u003cli\u003e2.5 Ω On Resistance\u003c\/li\u003e\n\u003cli\u003e0.75 Ω On-Resistance Flatness\u003c\/li\u003e\n\u003cli\u003e100 pA Leakage Currents\u003c\/li\u003e\n\u003cli\u003eSingle 8-to-1 Matrix Switch\u003c\/li\u003e\n\u003cli\u003ePower-On Reset\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.analog.com\/en\/products\/adg728.html\"\u003eDatasheets \u0026amp; App notes at Analog Devices\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eProduct Dimensions: 30.6mm x 17.8mm x 4.7mm \/ 1.2\" x 0.7\" x 0.2\"\u003c\/p\u003e\n\u003cp\u003eProduct Weight: 2.1g \/ 0.1oz\u003c\/p\u003e\n\n\n\u003cul id=\"product-files\"\u003e\u003c\/ul\u003e\n\u003cdiv class=\"row\"\u003e\n\u003cdiv class=\"col-lg-2 col-md-3 col-sm-3 col-xs-4\"\u003e\u003cimg src=\"https:\/\/www.adafruit.com\/includes\/templates\/shop2019\/images\/RoHS2_2011_65_EU.svg\" alt=\"RoHS 2 2011 65 EU Compliant\" width=\"145\" height=\"80\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"col-lg-2 col-md-3 col-sm-3 col-xs-4\"\u003e\u003cimg src=\"https:\/\/www.adafruit.com\/includes\/templates\/shop2019\/images\/RoHS2_2015_863_EU.svg\" alt=\"RoHS 2 2015 863 EU Compliant\" width=\"145\" height=\"80\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Adafruit","offers":[{"title":"Default Title","offer_id":56500165804405,"sku":"ADA5899","price":8.3,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0389\/1025\/files\/5899-00.jpg?v=1766148595","url":"https:\/\/wholesale.pimoroni.com\/en-us\/products\/adafruit-adg728-1-to-8-analog-matrix-switch-stemma-qt","provider":"Pimoroni Wholesale","version":"1.0","type":"link"}