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

20kΩ

1

7

8

4

2

3

6

5

1/2

OP200AZ

1/2

OP200AZ

40,000

–

+

5kΩ

5kΩ

–15V

+15V

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

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.

R3

1kΩ

R2

2kΩ

1/2

OP200AZ

1/2

OP200AZ

R1

1kΩ

C1

30pF

D1

1N4148

D1

1N4148

7

1

8

4

6

5

2

3

–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.

R5

100Ω

1

2

3

7

8

4

6

5

1/2

OP200EZ

1/2

OP200EZ

= 10mA/V

=

RS

100Ω

–15V

+15V

–

R1

10kΩ

+

R1

10kΩ

R3

10kΩ

R4

1kΩ

Figure 32. Precision Current Pump