OP467 Datasheet, PDF (14/16 Pages) Analog Devices – Quad Precision, High Speed Operational Amplifier

OP467
V_OUTA
V_OUTB
–2
1 OP467
+3
+15V
0.1␮F
4 _–6
7 OP467
11 + 5
0.1␮F
–15V
+5V
+10V
1 V_DD
DGND 28
DAC8408
2 V_REFA
V_REFC 27
C1
10pF
3 R_FBA
4 IOUT 1A
5 ^{IOUT 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 RFBB
R_FBD 22
C2
10pF
+10V
8 V_REFB
9 DB0 (LSB)
10 DB1
V_REFD 21
DS2 20
DS1 19
11 DB2
12 DB3
R/W 18
A/B 17
13 DB4
(MSB) DB7 16
14 DB5
DB6 15
+10V
+10V
DIGITAL
CONTROL
SIGNALS
C3
10pF
13
OP467 14
12 +
V_OUTA
C4
10pF
9
OP467 8
10 +
V_OUTB
Figure 46. Quad DAC Unipolar Operation
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 variety of
applications. The circuit in Figure 46 is a unipolar quad D/A
converter 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. Figures 47 and 48 show the full-scale settling
time of the outputs. To obtain reliable circuit performance, keep
the traces from the DAC’s I_OUT to the inverting inputs of the
OP467 short to minimize parasitic capacitance.
251.0ns
100
90
10
0%
2V
50mV
100ns
260.0ns
100
90
10
0%
2V
50mV
100ns
Figure 47. Voltage Output Settling Time
Figure 48. Voltage Output Settling Time
DAC-8408
R_FB
3pF
I_OUT
I-V
OP467
DC OFFSET
2k⍀
2k⍀
AD847
1k⍀
604⍀
60.4⍀
50⍀
Figure 49. DAC V_OUT Settling Time Circuit
–14–
REV. C