UNIVERSAL AMPLIFIER IC

AM400

analog microelectronics

October 2005

Analog Microelectronics GmbH

Phone:

+49 (0)6131/91 073 – 0

16/21

An der Fahrt 13, D – 55124 Mainz

Fax:

+49 (0)6131/91 073 – 30

Rev.: 4.2

Internet: http://www.analogmicro.de

Email:

info@analogmicro.de

where













+

=

=

2

1

1

5

R

R

G

G

G

GAIN

IA

I

and

4

3

4

0

2

R

R

R

R

V

I

REF

SET

+

⋅

=

the AM400 circuitry are to be dimensioned in such a way that the output current has a range of

4...20mA.

As only the current output is to be used, the gain and output current range can be dimensioned using

27

Ω. Observing the boundary conditions for the external components the following values are then

obtained:

In this specific application particular attention must be paid to the current consumption which at a

temperature of 85°C may not exceed 4mA.

Negative offset voltages can be

compensated for using pin ZA.

If the pin is not in use it

be

connected to IC ground GND.

must

Ground

V

S

I

OUT

R

1

R

2

R

IAL

R

3

R

4

C

1

R

0

T

1

D

1

R

5

R

L

R

SET

2-wire

connection

C

2

IC ground: GND

System ground: Ground

GND

V

BG

17

5

IA

7

6

10

18

15

14

13

12

11

20

V

I

16

19

Voltage reference

1

9

OP1

8

3

4

2

AM400-0

OP2

OP3

Figure 7:

Typical 2-wire application for differential input signals