dac16fs Analog Devices, Inc., dac16fs Datasheet - Page 9

• Manufacturer Part Number: dac16fs
• Description: 16-bit High Speed Current-output Dac
• Manufacturer: Analog Devices, Inc.

REV. B
Bipolar Configuration
For applications that require a bipolar output voltage, the circuit
in Figure 24 can be modified slightly by adding a resistor from
the reference to the inverting sum node of the output amplifier
to level shift the output signal. The transfer equation for the cir-
cuit now becomes:
The circuit has the form shown in Figure 25, and Table IV pro-
vides the relationship between the digital input code and the
circuit’s output voltage for the component values shown.
V
O
R4 8 I
REF
+5V
0.1 F
10 F
+5V
0.1 F
10 F
65,535 – Digital Code
REF02
+15V
0.1 F
REF02
+15
V
65,536
DIGITAL +5V
PIN 3, DAC16
0.1 F
DIGITAL +5V
PIN 3, DAC16
+5V
5k
R1
22 F
REF
47 F
22 F
5k
R1
CLK
47 F
EN
CLK
Figure 24. Unipolar Circuit Configuration
EN
Figure 25. Bipolar Circuit Configuration
–15V
5k
R2
–15V
– V
5k
R2
100nF
CERAMIC
REF
100nF
CERAMIC
DB0 – DB7
74AC11377
I
C
REF GND
REF
COMP
74AC11377
DB0 – DB7
I
C
REF GND
REF
DIGITAL INPUT WORD
COMP
DIGITAL INPUT WORD
R4
R3
8
8
DAC16
–9–
–15V
DAC16
–15V
8
10 F
DB8 – DB15
74AC11377
Digital Input
Word (Hex)
0000
7FFE
7FFF
8000
FFFF
0.1 F
AGND
10 F
8
DB8 – DB15
Table IV. Bipolar Output Operation vs. Digital Input Code
74AC11377
I
0.1 F
AGND
OUT
I
OUT
RESISTORS:
CADDOCK T912–5K–010–02 (OR EQUIVALENT)
5k , 0.01%, TC TRACK = 2 ppm/ C
RESISTORS:
CADDOCK T912–5K–010–02 (OR EQUIVALENT)
5k
+5V
, 0.01%, TC TRACK = 2 ppm/ C
REF
R3
2.5k
(5k
OP97A
+15V
–15V
(5k
OP97A
2.5k
+15V
–15V
R3
2)
Decimal Number in
DAC Decoder
65,535
32,769
32,768
32,767
0
10 F
10 F
0.1 F
0.1 F
2)
10 F
10 F
0.1 F
0.1 F
(5k
2.5k
R4
2)
V
0V TO +10V FS
OUT
V
OUT
5V FS
Analog Output
Voltage (V)
4.999848
152E-6
0
–152E-6
–5.00000
DAC16