1 MW

50 kW

52.6316 kW

50 kW

2.7778 kW

1 MW

7

3

2

6

4

1

A1

INA148

–15 V

V

O

+15 V

C

1

4.7 µF

250 V

(1)

C

2

4.7 µF

250 V

(1)

V

CM = 200 Vpk

V

+IN

V

–IN

V = (V

– V

)

O

+IN

–IN

Copyright © 2016, Texas Instruments Incorporated

17

INA148-Q1

www.ti.com

SBOS472B – MARCH 2009 – REVISED JUNE 2016

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Copyright © 2009–2016, Texas Instruments Incorporated

8.2.3.1 Design Requirements

For this design example, use the parameters listed in Table 3 as the input parameters.

Table 3. Design Parameters

PARAMETER

EXAMPLE VALUE

Common-mode voltage

–23 V to 56 V

Load current

Bidirectional

Reference voltage (LM4041-N-Q1)

1.235 V ± 0.1%

Supply voltage (INA148-Q1)

5 V

8.2.3.2 Detailed Design Procedure

For applications that have –23-V to 56-V common-mode voltage and a single 5-V supply, the common-mode

rejection ratio is in the order of 80 dB. The INA148-Q1 is not a rail-to-rail output. An external reference voltage is

necessary for bidirectional measurment or low differential output. The external resistor is necessary to provide a

100-µA supply to LM4041-N-Q1.

8.2.4 AC-Coupled Difference Amplifier

(1)

Metallized polypropylene, ±5% tolerance

Figure 29. AC-Coupled Difference Amplifier Circuit Diagram

8.2.4.1 Design Requirements

For this design example, use the parameters listed in Table 4 as the input parameters.

Table 4. Design Parameters

PARAMETER

EXAMPLE VALUE

Decoupling capacitors

4.7 µF, 250 V ± 5%

Differential input voltage range

–14 V to 14 V