J-Testr ADC/DAC Breakout Card

About

The ADC/DAC Breakout card gives access to all the differential DAC lines directly via clearly identified 1mm diameter test-point holes. Each DAC differential pair is on a 2.54mm pitch allowing the use of standard 2-pin SIL headers if required.

The ADC lines are also taken to clearly identified 1mm diameter test-point holes with a 2.54mm pitch allowing the use of standard 2-pin SIL heads if required. However, for the ADC there is a network of four 0603 resistors to allow the following:

Direct connection through (Standard with zero ohm)
Differential divider
Single ended configuration
Single ended divider 

​​These resistors allow the user to experiment with different measurement configurations and also allow high voltages to be measured with appropriate divider resistors fitted.

An external precision 2.048V reference is connected to both DAC groups A and B. To use the reference the user must connect its power to an external 5V system supply via ‘TP17’ or by attaching it  to AVCC with a low value resistor (< 20milli Ohm or Link) at position R36.
Both AVCC and AVSS are also available at 1mm test-point holes for convenience.

The ADC/DAC Breakout card UserIO (GPIO) lines are taken to eight clearly marked 1mm diameter test-point holes. The card also contains 2 extra common grounding points.
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​Schematic (PDF also available on download page)