9

®

DAC716

Using D/A Converters

The GAIN ADJUST and OFFSET ADJUST circuits of

DAC716 have been arranged so that these points may be

easily driven by external D/A converters. Refer to

Figure 7. 12-bit D/A converters provide a nominal

OFFSET adjust and GAIN adjust resolution of 25

µV and

15

µV per LSB step, respectively.

Nominal values of GAIN and OFFSET occur when the D/A

converters outputs are at approximately half scale, 0V.

OUTPUT VOLTAGE RANGE CONNECTIONS

The DAC716 output amplifier is connected internally for

10V output range.

DIGITAL INTERFACE

SERIAL INTERFACE

The DAC716 has a serial interface with two data buffers

which can be used for either synchronous or asynchronous

updating of multiple D/A converters. A0 is the enable control

for the Data Input Latch. A1 is the enable for the D/A Latch.

CLK is used to strobe data into the latches enabled by A0 and

A1. A CLR function is also provided and when enabled it sets

both the Data Latch and the D/A Latch to all zeros .

Multiple DAC716s can be connected to the same CLK and

data lines in two ways. The output of the serial loaded data

latch is available as SDO so that any number of DAC716s

can be cascaded on the same input bit stream as shown in

Figure 8 and 9. This configuration allows all D/A converters

to be updated simultaneously and requires a minimum num-

ber of control signal inputs. These configurations do require

16N CLK cycles to load any given D/A converter, where N

is the number of D/A converters.

The DAC716 can also be connected in parallel as shown in

Figure 10. This configuration allows any D/A converter in

the system to be updated in a maximum of 16 CLK cycles.

FIGURE 5. System Ground Considerations for High-Resolution D/A Converters.

R

1

Sense

Output

R

L

R

2

R

3

Alternate Ground

Sense Connection

System Ground

ACOM

DCOM

Bus

Interface

DAC716

Analog

Power

Supply

0.01µF

(1)

0.01µF

To +V

CC

To –V

CC

NOTE: (1) Locate close to DAC716 package.

V

OUT

5k

Ω

9.75k

Ω

V

REF

V

REF OUT

Offset Adjust

SDI

A

0

A

1

CLR