AD565 Analog Devices, AD565 Datasheet - Page 10

• Manufacturer Part Number: AD565
• Description: High Speed 12-Bit Monolithic D/A Converters
• Manufacturer: Analog Devices

AD565A/AD566A
FIGURE 6. OTHER VOLTAGE RANGES
The AD566A can also be easily configured for a unipolar 0 volt
to +5 volt range or ± 2.5 volt and ± 10 volt bipolar ranges by
using the additional 5k application resistor provided at the 20
volt span R terminal, Pin 11. For a 5 volt span (0 V to +5 V or
± 2.5 V), the two 5k resistors are used in parallel by shorting Pin
11 to Pin 9 and connecting Pin 10 to the op amp output and the
bipolar offset resistor either to ground for unipolar or to V
for the bipolar range. For the ± 10 volt range (20 volt span) use
the 5k resistors in series by connecting only Pin 11 to the op
amp output and the bipolar offset connected as shown. The
± 10 volt option is shown in Figure 6.
–V
7.5V
14k
E
AD561
*
THE PARALLEL COMBINATION OF THE BIPOLAR OFFSET RESISTOR
AND R3 ESTABLISHES A CURRENT TO BALANCE THE MSB CURRENT.
THE EFFECT OF TEMPERATURE COEFFICIENT MISMATCH BETWEEN
THE BIPOLAR RESISTOR COMBINATION AND DAC RESISTORS IS
EXPANDED ON PREVIOUS PAGE.
REF
GND
5k
REF
R2
Fgure 6. ± 10 V Voltage Output
REF
IN
–V
20k
AD566A
EE
19.95k
POWER
GND
0.5mA
I
REF
9.95k
5k
R1
MSB
INPUT
CODE
I
4
OUT
DAC
BIPOLAR OFF
5k
5k
CODE
I
REF
=
I
LSB
O
8k
DAC
OUT
10V SPAN
20V SPAN
2.4k
26k *
AD509
R3
10pF
REF
–10–
DIGITAL INPUT
MSB
0 0 0 0 0 0 0 0 0 0 0 0
0 1 1 1 1 1 1 1 1 1 1 1
1 0 0 0 0 0 0 0 0 0 0 0
1 1 1 1 1 1 1 1 1 1 1 1
*Inverts the MSB of the offset binary code with an external inverter to obtain
twos complement.
LSB
Table I. Digital Input Codes
Straight Binary
Zero
Mid Scale – 1 LSB
+1/2 FS
+FS – l LSB
ANALOG OUTPUT
Offset Binary
–FS
Zero – 1 LSB
Zero
+ FS – 1 LSB
Twos Compl.*
Zero
+FS – 1 LSB
–FS
Zero – 1 LSB
REV. D