What is the purpose of Rfb in the DAC TLC7524C do?

[matrixofdynamism]

The datasheet for this part can be found here https://www.ti.com/lit/ds/slas061d/slas061d.pdf.

1. The datasheet shows pin 16 as Rfb but does not explain its purpose. What does it do?
2. Also, there are two outputs on pins 1 & 2, is one of them to be always grounded as shown in Figure 3 and Figure 4? If so, then why even include it and not have just a single output?
3. Is it not possible to connect a voltmeter directly across pin 1 or pin 2 (and GND) to measure the output voltage of the ADC or must an op-amp to convert the current to voltage always be connected at the output?

 

[barry]

1) RFb is an input for gain adjustment.
2) Just because two applications show a pin grounded doesn't mean it's "always grounded".
3) The DAC is current output, not voltage output; connecting a voltmeter across its output is meaningless.
4) I think you need to study up on multiplying DACs. First, read the The Principles of Operation section of the data sheet.
5) You can get a voltage-output DAC.

 

[matrixofdynamism]

Since a current to voltage converter will be needed for this, why not build it into the design of the DAC itself to make things more convinient

 

[barry]

Since a current to voltage converter will be needed for this, why not build it into the design of the DAC itself to make things more convinient

For the same reason there's not a power amp and a motor with a chicken on the end of the shaft built in to the design; because different applications have different requirements.