AM452 – Voltage-to-current transducer IC

with a differential input

Analog Microelectronics GmbH

An der Fahrt 13, D – 55124 Mainz

February 2008 - Rev 1.2 - Page 11/21

Phone: +49 (0)6131/91 073-0

Fax:

+49 (0)6131/91 073-30

Email: info@analogmicro.de

Differences in the AM452 circuitry with 2- and 3-wire applications

Figure 4: Differences in 2-and 3-wire circuitry in conjunction with AM452

AM452 is constructed in such a way that by changing the external circuitry it is suitable for

both 2-wire and 3-wire operation.

In 3-wire operation (see Figure 4, right) the IC's connection to ground (pin 14 or GND) is

connected to the system ground (Ground) which is applied externally. System supply voltage

directly into AM452 (power consumption).

and pin 10 (VCC) to pin 9 (RS-). The overall current including the supply current then flows

Ground

V

S

I

OUT

R

0

T

1

D

1

R

5

R

L

GND

14

11

9

8

10

SET Stage

3-wire connection

V/I Converter

Ground

V

S

I

OUT

R

0

T

1

D

1

R

5

R

L

2-wire

connection

C

2

GND

14

11

9

8

10

V/I Converter

SET Stage