ad7523kn Intersil Corporation, ad7523kn Datasheet - Page 6

• Manufacturer Part Number: ad7523kn
• Description: 8-bit, Multiplying D/a Converters
• Manufacturer: Intersil Corporation

Offset Adjustment
Gain Adjustment
Bipolar (Offset Binary) Operation - AD7533
The circuit configuration for operating the AD7533 in the
bipolar mode is given in Figure 3. Using offset binary digital
input codes and positive and negative reference voltage val-
ues, 4-Quadrant multiplication can be realized. The “Digital
Input Code/Analog Output Value” table for bipolar mode is
given in Table 4.
A “Logic 1” input at any digital input forces the corresponding
ladder switch to steer the bit current to I
input forces the bit current to I
I
OUT1
1. Adjust V
2. Connect all digital inputs to “Logic 1”.
3. Adjust I
4. Connect MSB (Bit 1) to “Logic 1” and all other bits to
5. Adjust I
1. Connect all digital inputs to V+.
2. Monitor V
3. To increase V
4. To decrease V
I
“Logic 0”.
at V
250 between V
250
terminal.
OUT2
and I
OUT
amplifier output.
between the reference voltage and the V
OUT2
OUT1
REF
.
OUT2
DIGITAL
OUT
INPUT
to approximately +10V.
amplifier offset adjust trimpot for 0V 1mV at
OUT
amplifier offset adjust trimpot for 0V 1mV
OUT
for a -V
bus currents are complements of one
OUT
, connect a series resistor, R2, of up to
, connect a series resistor, R1, of up to
MAGNITUDE
and R
REF
SIGN BIT
(1
BITS
OUT2
FEEDBACK
1
/
2
8
) volts reading.
bus. For any code the
MSB
FIGURE 4. 10-BIT AND SIGN MULTIPLYING DAC
LSB
OUT1
ANALOG INPUT
.
V
GND
bus. A “Logic 0”
BIPOLAR
REF
4
13
AD7533
10V
15
AD7523, AD7533
3
V+
14
16
1
2
REF
OUT2
OUT1
R
10-13
FEEDBACK
another. The current amplifier at I
I
output sums the two currents. This configuration doubles the
output range. The difference current resulting at zero offset
binary code, (MSB = “Logic 1”, all other bits = “Logic 0”), is cor-
rected by using an external resistor, (10M ), from V
I
NOTES:
OUT2
OUT2
1. V
2. Nominal Full Scale for the circuit of Figure 6 is given by:
3. Nominal LSB magnitude for the circuit of Figure 3 is given by:
6
+
-
FSR
LSB
OUT
.
current and the transconductance amplifier at I
DIGITAL INPUT
TABLE 4. UNlPOLAR BINARY CODE - AD7533
=
1111111111
1000000001
1000000000
0111111111
0000000001
0000000000
as shown in the Functional Diagram.
=
MSB LSB
V REF
V REF
10K
--------- -
512
1023
------------ -
512
1
1
/
2
.
5K
IH5140
.
6
-
+
0
+V REF
+V REF
+V REF
NOMINAL ANALOG OUTPUT
-V REF
-V REF
10K
OUT2
changes the polarity of
511
--------- -
512
--------- -
512
--------- -
512
511
--------- -
512
512
--------- -
512
1
1
(NOTE 1)
V
OUT
REF
OUT1
to