Texas Instruments Low-Power, Rail-to-Rail Output, 16-Bit Serial Input DIGITAL-TO-ANALOG CONVERTER DAC8531EVM DAC8531EVM Hoja De Datos
Los códigos de productos
DAC8531EVM
Host Processor Interface
3-9
EVM Operation
Table 3–5. Capacitive Load Drive Output Jumper Settings
Reference
Jumper
Setting
Function
W7
2–3
Select 5 V for the positive rail supply of the op-amp if W12 is closed
W8
1–2
Negative rail of the op-amp tied to analog GND
W10
Open
Disconnect V
REF
from negative input of op-amp
W11
Open
(see Note)
Disconnect R12 (see Note)
W12
Close
Supplies the constant 5 V to the positive rail of the op-amp if W7, pins 2 and 3,
are shorted together
are shorted together
W13
5–6
Buffered output of DAC is channeled to the output terminals
Note:
If there is a need to incrementally adjust the capacitive load output, replace R12 with a capacitor with the desired capaci-
tance value and close W11.
tance value and close W11.
3.2.3
Bipolar Operation Using the DAC8531
Although the DAC8531 has been designed for single-supply operation, the
bipolar output of operation is implemented using the circuit shown in
Figure 3–7. The output of the circuit is an output voltage range of
bipolar output of operation is implemented using the circuit shown in
Figure 3–7. The output of the circuit is an output voltage range of
±
V
REF
.
The
rail-to-rail operation at the amplifier output is achievable using an OPA350 as
the output amplifier.
the output amplifier.
Figure 3–7. Bipolar Operation With the DAC8531
_
+
5 V
–5 V
OPA350
R2
10 k
Ω
R1
10 k
Ω
U11
V
FB
V
OUT
V
REF
Three-Wire
Serial Interface
0.1
µ
F
10
µ
F
V
REF
DAC8531
U12
±
5 V
The EVM requires an additional
±
15-V power supply to provide the supply rails
for the OPA177 op-amp, U17. The
±
15-V supply is provided through the J1
connector of the EVM. The 15 V is attached to J1-3 terminal and the –15 V is
attached to J1-1 terminal. The
attached to J1-1 terminal. The
±
15-V supplies are referenced to J1-2 terminal.
The OPA177 op-amp is specifically used to generate the –5-V supply voltage
for the negative rail of the OPA350 op-amp circuit, U12.
for the negative rail of the OPA350 op-amp circuit, U12.
The bipolar configuration is accomplished by following the correct jumper
settings according to Table 3–6.
settings according to Table 3–6.