TLC7225C, TLC7225I

QUADRUPLE 8-BIT DIGITAL-TO-ANALOG CONVERTERS

SLAS109B – OCTOBER 1996 – REVISED FEBRUARY 2001

16

POST OFFICE BOX 655303

APPLICATION INFORMATION

digital word multiplication

Since each DAC of the TLC7225 has a separate reference input, the output of one DAC can be used as the

reference input for another. Therefore, multiplication of digital words can be performed (with the result given in

can be expressed as given in equation 2:

(2)

In this manner, the four DACs can be used on their own or in conjunction with an external summing amplifier

to generate complex waveforms. Figure 13 shows one such application with the output waveform, Y, which is

represented by equation 3:

(3)

where x is the digital code that is applied to all four DAC latches.

_

+

REFA

REFB

REFC

REFD

OUTA

OUTB

OUTC

OUTD

AGND

DGND

VSS

15 V

Y

TLC7225†

VI

† Digital inputs omitted for clarity

100 k

Ω

50 k

Ω

33 k

Ω

50 k

Ω

25 k

Ω

100 k

Ω

VDD

Figure 13. Complex-Waveform Generation