DAC8541

SLAS353 − DECEMBER 2001

18

www.ti.com

APPLICATION INFORMATION

16 Bits

D[15:0]

CS

R/W

LDAC

VREFL

DGND

AVDD

DVDD

VOUTSENSE

VOUT

VREFH

AGND

(Other Connections Omitted for Clarity)

0.1

µF

1 to 10

µF

0.1

µF

10

µF

0.1

µF

10

µF

AVDD

DVDD

VOUT

VREF

D[15:0]

A[23:0]

IOSTRB

R/W

XF(I/O)

TMS320C5402

DAC8541

Address

Decoder

EN

Figure 33. DAC8541 to TMS320 DSP

bipolar operation using the DAC8541

The DAC8541 has been designed for single-supply operation but a bipolar output range is also possible using

the circuit shown in Figure 34. The circuit allows the DAC8541 to achieve an analog output range of

±5 V.

Rail-to-rail operation at the amplifier output is achievable using an OPA703 as the output amplifier.

When operated with BTC/USB set high, the output voltage for any input code can be calculated as follows:

V

OUT +

V

REF

H

D

65536

R1

) R2

R1

* V

REF

H

R2

R1

V

OUT +

10

D

65536

* 5V

This is an output voltage range of

±5 V with 8000h corresponding to a –5 V output and 7FFFh corresponding

to a 5 V output. Bipolar zero is given by 0000h applied to the DAC.

VOUT

VOUTSense

VREFH

VREFL

R1 = 10 k

Ω

5 V

−5 V

R2 = 10 k

Ω

±5 V

DAC8541

0.1

µF

10

µF

5 V

(Other Pins Omitted for Clarity)

OPA703

−

+

Figure 34. Bipolar Operation With the DAC8541