9

DAC80/80P

®

Driving a Resistive Load Unipolar

A load resistance, R

Figure 11 will generate a voltage range, V

by:

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no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change

without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant

any BURR-BROWN product for use in life support devices and/or systems.

V

The unipolar output impedance R

R

LI

is the internal load resistance of 968

Ω (derived by

connecting pin 15 to 20 and pin 18 to 19). By choosing R

LS

= 210

Ω, R

load. This gives an output range of 0 to –2V. Since R

exact, initial trimming per Figure 3 may be necessary; also

R

Driving a Resistive Load Bipolar

The equivalent output circuit for a bipolar output voltage

range is shown in Figure 12, R

L

= R

LI

+ R

V

OUT

is

determined by:

V

By connecting pin 17 to 15, the output current becomes

bipolar (

±1mA) and the output impedance R

O

becomes

3.2k

Ω (6.6kΩ in parallel with 6.3kΩ). R

by connecting pin 15 to 18 and pin 18 to 19). By choosing

R

total load. This gives an output range of

±1V. As indicated

above, trimming may be necessary.

FIGURE 12. Current Output Model Connected for Bipolar

Output Voltage with Resistive Load.

21

15

+1mA

V

OUT

–

R

LI

R

O

Current Controlled

by Digital Input

+

Common

R

LS

20

FIGURE 11. Current Output Model Equivalent Circuit

Connected for Unipolar Voltage Output with

Resistive Load.

21

15

0 to

–2mA

V

OUT

–

R

LI

R

O

Current Controlled

by Digital Input

+

Common

R

LS

18