Jumper Setting

3.3 Jumper Setting

The figures in Table 3-5 will show the function of each jumper on the EVM.

Table 3-5. Jumper Setting Function

Reference

Jumper

Function

 

Setting

 

 

 

 

 

 

 

 

 

 

 

1

 

3

ROFFSET is strapped to VREF to set VSJ (summing junction) to VREF/2. Refer to the data

 

 

 

 

 

 

sheet for offset adjustment.

 

 

 

 

 

 

 

W1

1

 

3

ROFFSET is not connected to set VSJ (summing junction) to VREF/3. Refer to the data

 

 

 

 

 

sheet for offset adjustment.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

3

ROFFSET is strapped to AGND to set VSJ (summing junction) to VREF/6. Refer to the

 

 

 

 

 

 

data sheet for osset adjustment.

 

 

 

 

 

 

 

 

1

 

3

Disables the internal reference voltage.

W2

 

 

 

 

 

 

 

 

 

 

 

 

1

 

3

Enables the internal reference voltage of +10V.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

3

REFIN is strapped to REFOUT to allow the internal 10 V to supply the DAC reference

W3

 

 

 

 

 

voltage.

 

 

 

 

 

 

1

 

3

REFIN is strapped to exREFin to allow either the onboard adjustable reference or user

 

 

 

 

 

 

 

 

supplied reference to supply the DAC reference voltage.

 

 

 

 

 

 

 

 

1

 

3

Routes the onboard 10 V reference through the adjustable pot to W3 and W14.

W4

 

 

 

 

 

 

 

 

 

 

 

 

1

 

3

Routes the user supplied reference from TP1 or J4-20 through the adjustable pot to

 

 

 

 

 

 

 

 

W3 and W14.

 

 

 

 

 

 

 

 

1

 

3

 

Negative supply rail of op-amp is powered by -15 V.

W5

 

 

 

 

 

 

 

 

 

 

 

 

1

 

3

 

Negative supply rail of op-amp is tied to AGND.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

W6

 

 

 

 

 

REFADJ pin is not connected.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REFADJ pin is connected to R1 pot for gain adjustment input when internal reference

 

 

 

 

 

 

 

 

 

 

 

 

is used.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RFB2 pin is not connected to the VOUT pin.

 

 

 

 

 

 

W7

W8

RFB2 pin is strapped to the VOUT pin for feedback.

TEST pin not connected to DGND.

TEST pin connected to DGND (default mode).

SJ (summing junction) pin of the DAC output amplifier is not connected.

W9

 

 

 

SJ (summing junction) pin of the DAC output amplifier is connected to R2 pot to allow

 

 

 

 

 

 

 

 

 

 

small amount of current for offset adjustment.

 

 

 

 

 

 

 

 

 

 

W10

 

 

 

 

RFB1 pin is not connected.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RFB1 pin is strapped to RFB2 pin for DAC VOUT feedback.

EVM Operation

3-5

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Image 25
Texas Instruments DAC7741EVM manual Jumper Setting Function, Reference Jumper Function