Datasheet

OP200 Data Sheet
Rev. G | Page 12 of 16
APPLICATIONS INFORMATION
The OP200 is inherently stable at all gains and is capable of
driving large capacitive loads without oscillating. Nonetheless,
good supply decoupling is highly recommended. Proper supply
decoupling reduces problems caused by supply line noise and
improves the capacitive load driving capability of the OP200.
DUAL LOW POWER INSTRUMENTATION
AMPLIFIER
A dual instrumentation amplifier that consumes less than 33 mW
of power per channel is shown in Figure 30. The linearity of the
instrumentation amplifier exceeds 16 bits in gains of 5 to 200 and is
better than 14 bits in gains from 200 to 1000. CMRR is above
115 dB (gain = 1000). Offset voltage drift is typically 0.2 μV/°C
over the military temperature range, which is comparable to the
best monolithic instrumentation amplifiers. The bandwidth of
the low power instrumentation amplifier is a function of gain
and is shown in Table 7.
Table 7. Gain Bandwidth
Gain
Bandwidth
5 150 kHz
10
67 kHz
100 7.5 kHz
1000 500 Hz
00322-030
20kΩ
1
7
8
4
2
3
6
5
1/2
OP200AZ
1/2
OP200AZ
V
OUT
V
IN
V
OUT
= 5 +
V
IN
+ V
REF
40,000
R
G
–
+
5kΩ
5kΩ
R
G
–15V
+15V
V
REF
20kΩ
Figure 30. Dual Low Power Instrumentation Amplifier
The output signal is specified with respect to the reference
input, which is normally connected to analog ground. The
reference input can be used to offset the output from −10 V
to +10 V if required.
PRECISION ABSOLUTE VALUE AMPLIFIER
The circuit in Figure 31 is a precision absolute value amplifier
with an input impedance of 10 MΩ. The high gain and low TCV
OS
of the OP200 ensure accurate operation with microvolt input
signals. In this circuit, the input always appears as a common-
mode signal to the op amps. The CMRR of the OP200 exceeds
120 dB, yielding an error of less than 2 ppm.
00322-031
R3
1kΩ
R2
2kΩ
1/2
OP200AZ
1/2
OP200AZ
V
OUT
0V < V
OUT
< 10V
R1
1kΩ
C1
30pF
D1
1N4148
D1
1N4148
7
1
8
4
6
5
2
3
V
IN
–15V
+15V
C2
0.1pF
C2
0.1pF
Figure 31. Precision Absolute Value Amplifier
PRECISION CURRENT PUMP
The maximum output current of the precision current pump
shown in Figure 32 is ±10 mA. Voltage compliance is ±10 V
with ±15 V supplies. Output impedance of the current transmit-
ter exceeds 3 MΩ with linearity better than 16 bits.
00322-032
R5
100Ω
1
2
3
7
8
4
6
5
1/2
OP200EZ
1/2
OP200EZ
I
OUT
V
IN
I
OUT
= = 10mA/V=
V
IN
RS
V
IN
100Ω
–15V
+15V
–
R1
10kΩ
+
R1
10kΩ
R3
10kΩ
R4
1kΩ
Figure 32. Precision Current Pump