The Adafruit ADG729 Dual 1-to-4 Analog Matrix Switches provide an efficient and reliable alternative to mechanical relays, with a smaller and lower-power technology. This breakout allows for easy use of the tiny surface mount chips, enabling connection between two sets of four analog signals up to 5V without the need for complicated soldering.
The ADG729 utilizes I2C communication to enable/disable the 8 channels switches. Four channels are linked to the DA analog pin while the remaining four are linked to the DB analog pin. Unlike digital switches and multiplexers, these channels do not have designated 'input' and 'output' signals, as the signal direction is bidirectional. This allows for various signal routing options, such as using the DA or DB signal as input for 4 outputs, or the 4 inputs for a single output.
The ADG729 is not just a multiplexer, but a matrix switch with 8 separate switches. This allows for signal routing and combining multiple signals. For all 8 signals to be routed to one pin, consider the ADG728.
Unlike a relay or mechanical switch, analog switches don't wear out, and the switch time is near instant, about 100nS. The ADG729 chip also guarantees break-before-make so the deselected switches will open before selected switches close.
However, there's a few things to watch out for:
- The Vin power pin (the red wire if using a STEMMA QT cable) must as high as the highest analog voltages you want to switch. 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.
- It cannot switch signals below ground. No negative voltages can be applied to the Switch or DA/DB pins!
- Analog switches are for signals, not power! Since 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.
In addition to the 8 switch S pins and the two D pins that can be switched to, there's also two I2C address pins so you can change the default address from 0x44 up to 0x47.
To get you going fast, we spun up a custom-made PCB in the STEMMA QT form factor, making it easy to interface with. The STEMMA QT connectors on either side are compatible with the SparkFun Qwiic 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 compatible cable.
Technical Details
ADG729 Specifications
- I2C Interface
- 2.7 V to 5.5 V Single Supply
- 2.5 Ω On Resistance
- 0.75 Ω On-Resistance Flatness
- 100 pA Leakage Currents
- Dual 4-to-1 Matrix Switch
- Power-On Reset
- Datasheets & App notes at Analog Devices
Product Dimensions: 30.6mm x 17.8mm x 4.7mm / 1.2" x 0.7" x 0.2"
Product Weight: 2.1g / 0.1oz
Shipping rates Australia wide and New Zealand
FAQ:
- How do I estimate shipping for my order?
- Add products in the shopping cart and head to the checkout page to estimate the shipping.
Dispatch time
Unless expressly agreed otherwise with you, we will not commence delivery of an order until we have received cleared payment of the purchase price in full.
All orders placed before 11 am AEST (Monday to Friday) will ordinarily be processed on the same day.
We will endeavour to ship the Products by the applicable time indicated on the website, but all times are indicative only. All shipping times are dispatch times only, and actual delivery dates will depend on the shipping method chosen, delivery address and delivery service provider.
Note- Please make a note during purchase if you require any item urgently. However we cannot guarantee that we will be able to comply with any request.
*Go to Australia post delivery time calculation to get various Australia post service in your area please use our shipping postcode Thomastown, 3074 as the "from" address - https://auspost.com.au/parcels-mail/delivery-times.html?ilink=tools-open-deliv-times.
We ship all products throughout mainland Australia, Tasmania and New Zealand - Including Darwin, Melbourne, Sydney, Tasmania, Adelaide, Brisbane, Perth, all metro and regional areas but do not deliver to areas in Australia where the Australia Post delivery network is not available.
Check Express shipping delivery coverage area at - http://auspost.com.au/parcels-mail/delivery-areas.html
Receipt of deliveries
Deliveries to post office boxes are not permitted where delivery is by courier. If delivery is by courier and nobody is available at the delivery address to accept delivery when delivery is attempted then the courier may either:
- leave the relevant parcel at the unattended address (the courier will do so if specified in your delivery requirements); or
- re-attempt delivery at a later time or date, in which case we may charge you an additional re-delivery fee.
Note that if a delivery is left unattended at the shipping address and is subsequently stolen then the theft is your responsibility, not ours.
Payment & Security
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.