TLC7225C, TLC7225I

QUADRUPLE 8-BIT DIGITAL-TO-ANALOG CONVERTERS

SLAS109B – OCTOBER 1996 – REVISED FEBRUARY 2001

12

POST OFFICE BOX 655303

APPLICATION INFORMATION

unipolar output operation

The unipolar output operation is the basic mode of operation for each channel of the TLC7225, with the output

to DGND to prevent parasitic transistor turnon. Connections for the unipolar output operation are shown in

Figure 8. The transfer values are shown in Table 3.

_

+

DAC A

_

+

DAC B

_

+

DAC C

_

+

DAC D

5

REFA

2

1

24

23

OUTA

OUTB

OUTC

OUTD

REFB

REFC

REFD

VSS

AGND

DGND

4

21

20

Figure 8. Unipolar Output Circuit

LSB

MSB

DAC LATCH CONTENTS

ANALOG OUTPUT

) V

ref

255

256

1111

1111

) V

ref

129

256

1000

0001

1000

0000

) V

ref

128

256

+)

V

ref

2

0111

1111

) V

ref

127

256

0000

0001

) V

ref

1

256

0000

0000

0 V

NOTE 3 : 1 LSB

+ V

ref

2– 8

+ V

ref

1

256

Table 3. Unipolar Code