Datasheet

1300 Henley Court

Pullman, WA 99163

509.334.6306

www.digilentinc.com

PmodR2R™ Reference Manual

Revised February 13, 2015

This manual applies to the PmodR2R rev. B

DOC#: 502-165

Other product and company names mentioned may be trademarks of their respective owners.

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Overview

The Digilent PmodR2R is an 8-bit Digital-to-Analog converter. It may not look as sleek and professional as some of

the other DACs that are out there, but on a fundamental level that is easy to see, this Pmod does exactly the same

thing as its counterparts.

1 Functional Description

The PmodR2R accepts 8 bits in parallel, either at a logic low or high voltage, which then go through a resistor

ladder to output a desired voltage. The “R2R” resistor ladder is one of the most popular ways that digital-to-analog

converters take a set of digital inputs and create a single analog output, requiring just two resistor values of R and

2*R. Because this Pmod only uses 10K Ω and 20K Ω resistors, very little current is drawn from the input pins.

2 Interfacing with the Pmod

The PmodR2R communicates with the host board via the GPIO protocol. Each of the 8 input pins are expected to

send out either a logic high or logic low voltage signal in such a way that represents the desired binary ratio of the

full analog output.

The PmodR2R.

 8-bit digital to analog conversion at up to

25MHz

 Easy attachment of oscilloscopes to

illustrate the data conversion process

Features include:

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300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com PmodR2R™ Reference Manual Revised February 13, 2015 This manual applies to the PmodR2R rev. B Overview The Digilent PmodR2R is an 8-bit Digital-to-Analog converter. It may not look as sleek and professional as some of the other DACs that are out there, but on a fundamental level that is easy to see, this Pmod does exactly the same thing as its counterparts.
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PmodR2R™ Reference Manual Pin Number (top row) 1 2 3 4 5 6 Header J1 Description Pin Number (bottom row) Data Bit 0 7 Data Bit 1 8 Data Bit 2 9 Data Bit 3 10 Ground 11 VCC 12 Description Data Bit 4 Data Bit 5 Data Bit 6 Data Bit 7 Ground VCC Table 1. Pinout description table. 3 Physical Dimensions The pins on the pin header are spaced 100 mil apart. The PCB is 1 inch long on the sides parallel to the pins on the pin header and 0.8 inches long on the sides perpendicular to the pin header.