OP467_15 Datasheet, PDF (16/20 Pages) Analog Devices – Quad Precision, High Speed Operational Amplifier

OP467
OUT A
OUT B
2
1 OP467
3
+15V
0.1µF
4
6
7 OP467
11
5
0.1µF
–15V
+5V
+10V
1 V_DD
DGND 28
DAC8408
2 V_REFA
V_REFC 27
C1
10pF
3 R_FBA
4 I_{OUT 1A}
5
I_{OUT 2A/}
I_{OUT 2B}
6 I_{OUT 1B}
R_FBC 26
I_{OUT 1C} 25
I_{OUT 2C/}
I_{OUT 2D}
24
I_{OUT 1D} 23
7 R_FBB
R_FBD 22
C2
10pF
+10V
8 V_REFB
9 DB0 (LSB)
10 DB1
V_REFD 21
DS2 20
DS1 19
11 DB2
R/W 18
12 DB3
A/B 17
13 DB4
(MSB) DB7 16
14 DB5
DB6 15
+10V
+10V
DIGITAL
CONTROL
SIGNALS
Figure 50. Quad DAC Unipolar Operation
C3
10pF
13
OP467 14
12
C4
10pF
9
OP467 8
10
OUT D
OUT C
FAST I-TO-V CONVERTER
The fast slew rate and fast settling time of the OP467 are well
suited to the fast buffers and I-to-V converters used in a variety
of applications. The circuit in Figure 50 is a unipolar quad DAC
consisting of only two ICs. The current output of the DAC8408
is converted to a voltage by the OP467 configured as an I-to-V
converter. This circuit is capable of settling to 0.1% within 200 ns.
Figure 51 and Figure 52 show the full-scale settling time of the
outputs. To obtain reliable circuit performance, keep the traces
from the IOUT of the DAC to the inverting inputs of the OP467
short to minimize parasitic capacitance.
260.0ns
100
90
10
0%
2V
50mV
100ns
Figure 51. Falling Edge Output Settling Time
251.0ns
100
90
10
0%
2V
50mV
100ns
Figure 52. Rising Edge Output Settling Time
DAC8408
R_FB
DC OFFSET
3pF
I_OUT
I-V
2kΩ
2kΩ
OP467
1kΩ
AD847
604Ω
60.4kΩ
50kΩ
Figure 53. DAC VOUT Settling Time Circuit
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