Datasheet

www.ti.com

EVM Operation

3.3 Analog Interface

For maximum flexibility, the DAC8831/32EVM is designed for easy interfacing to multiple analog sources.

Table 3 provides the pinout of connector J1. Samtec part numbers SSW-110-22-F-D-VS-K and

TSM-110-01-T-DV-P provide a convenient 10-pin, dual-row header/socket combination at J1. This

header/socket provides access to the analog output pins of the DAC through the onboard buffer amplifier.

Consult Samtec at www.samtec.com, or call 1-800-SAMTEC-9 for a variety of mating connector options.

Table 3. Pinout of J1

Pin Number Signal Description

J1-2 Vout Buffer voltage output – range depends on the position of SW1 (see section 3.3.1)

J1-4 Unused Pins are unused and should be left open for use with future amplifier and sensor output

modules.

J1-6 Unused

J1-8 Unused

J1-10 Unused

J1-12 Unused

J1-14 Unused

J1-16 Unused

J1-18 REF(–) Unused

J1-20 REF(+) External reference source input (1.25 V to 5.5 V maximum)

J1-15 Unused

J1-1–J1-19 (odd) AGND Analog ground connections (except J1-15)

3.3.1 EVM Output Voltage

Switch SW1 provides a means to allow unipolar or bipolar output operation of the DAC8831/32EVM.

When the slide switch is to the right (screen marked BIP), the output voltage on J1-2 is ±VREF. If the

onboard reference is used, this means that the output voltage is –2.5 Vdc to +2.5 Vdc. When the switch is

to the left (screen marked UNI), the output from the buffer is 0 V to +2.5 Vdc.

For a wider dynamic output range, the EVM can be configured to use an external reference by moving the

shunt at W1 to cover pins 2-3. In this case, an external reference from 1.25V to VDD may be applied to

J1-20. For best performance, the external reference must be supplied by a clean dc source. Take note

that the DAC output voltage may be limited by the input/output operating rails of the chosen output

amplifier.

SLAU202A–December 2006–Revised November 2009 DAC8831/32 Evaluation Module

Submit Documentation Feedback