DSP201 Burr-Brown Corporation, DSP201 Datasheet - Page 11

• Manufacturer Part Number: DSP201
• Description: DSP-Compatible Single/Dual DIGITAL-TO-ANALOG CONVERTERS
• Manufacturer: Burr-Brown Corporation

An alternative for calibrating on a bench is to tie SIN (DSP201
pin 13) or SINA and SINB (DSP202 pins 13 and 14) HIGH,
and provide a Bit Clock and periodic Convert Commands.
This loads 1111...1111 (FFFF
output to 1LSB below 0V. Then periodically bring RESET
(pin 8) LOW for at least two Convert Commands, which is
the equivalent of loading all 0s, so the output is 0V. Now
the output can be adjusted for an ideal transition step.
ADJUSTING BIPOLAR ZERO ERROR
zero error, the user should first adjust the MSB trim circuits,
and then use the offset adjust circuits to adjust the outputs to
0V with input codes of all 0s (0000...0000; 0000 hex or
00000 hex.) In this case, it is not possible to also trim offset
at –Full Scale, as described above.
FIGURE 2. DSP201 Power Supply Connections and Optional Adjust Circuits.
If it is important in a specific application to adjust bipolar
+5V
–5V
2.2µF
+
+
0.01µF
2.2µF
HEX
or 3FFFF
0.01µF
10
11
12
13
14
1
2
3
4
5
6
7
8
9
HEX
V –
AGNDB
V +
V +
), driving the
A
D
D
DSP201
DGND
DGND
AGND
AGND
VPOT
MSB
VOS
V +
V –
A
D
11
28
27
26
25
24
23
22
21
20
19
18
17
16
15
GAIN ERROR
Gain error on the DSP201 or DSP202 cannot be directly
adjusted. If required in a specific application, gain can be
trimmed out at the system level by adjusting the gain used
in an output amplifier stage, such as would be used in any
active output filter. In this case, the bipolar zero error should
be adjusted first as discussed above. Then, the gain on the
output amplifier should be adjusted to minimize the devia-
tion from ideal for –Full Scale (1000...000; 8000 hex or
20000 hex) and +Full Scale (0111...1111; 7FFF hex or
1FFFF hex.)
0.01µF
100k
0.01µF
+
MSB Adjust
2.2µF
100k
3.3k
+
–5V
2.2µF
DSP201/202
–5V
+5V
–5V
Offset Adjust
100k
+5V
®