Datasheet

13
®
OPA627, 637
OPA627 OPA637
R
I
, R
1
2kΩ 500Ω
C
F
6pF 4pF
Error Band ±0.5mV ±0.2mV
(0.01%)
NOTE: C
F
is selected for best settling time performance
depending on test fixture layout. Once optimum value is
determined, a fixed capacitor may be used.
FIGURE 12. High Speed Instrumentation Amplifier, Gain = 100.
–In
+In
+
–
OPA637
Differential Voltage Gain = 1 + 2R
F
/R
G
2
3
–
+
–
+
INA105
Differential
Amplifier
1
6
5
Output
Gain = 100
CMRR 116dB
Bandwidth 1MHz
OPA637
25kΩ
25kΩ
25kΩ
25kΩ
Input Common-Mode
Range = ±5V
≈
≈
3pF
R
F
5kΩ
R
F
5kΩ
R
G
101Ω
–
+
±5V
Out
+15V
2kΩ
C
F
2kΩ
Error Out
R
I
R
I
51Ω
–15V
HP-
5082-
2835
High Quality
Pulse Generator
/
FIGURE 11. Settling Time and Slew Rate Test Circuit.
FIGURE 14. Composite Amplifier for Wide Bandwidth.
This composite amplifier uses the OPA603 current-feedback op amp to
provide extended bandwidth and slew rate at high closed-loop gain. The
feedback loop is closed around the composite amp, preserving the
precision input characteristics of the OPA627/637. Use separate power
supply bypass capacitors for each op amp.
GAIN A
1
R
1
R
2
R
3
R
4
–3dB SLEW RATE
(V/V) OP AMP (Ω)(kΩ)(Ω)(kΩ) (MHz) (V/
µs)
100 OPA627 50.5
(1)
4.99 20 1 15 700
1000 OPA637 49.9 4.99 12 1 11 500
NOTE: (1) Closest 1/2% value.
*Minimize capacitance at this node.
FIGURE 13. High Speed Instrumentation Amplifier, Gain = 1000.
+
–
OPA603
–
+
A
1
R
3
R
1
R
4
R
2
V
I
V
O
*
R
L
≥ 150Ω
for ±10V Out
–In
+In
+
–
OPA637
Differential Voltage Gain = (1 + 2R
F
/R
G
) • 10
2
3
–
+
–
+
INA106
Differential
Amplifier
1
6
5
Output
Gain = 1000
CMRR 116dB
Bandwidth 400kHz
OPA637
10kΩ
10kΩ
100kΩ
100kΩ
Input Common-Mode
Range = ±10V
≈
≈
3pF
R
F
5kΩ
R
F
5kΩ
R
G
101Ω