Industrial V/I Converter and Protector IC

AM462

analog microelectronics

December2006

Analog Microelectronics GmbH

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

6/20

An der Fahrt 13, D – 55124 Mainz

Fax:

+49 (0)6131/91 073 – 30

Rev. 2.4

Internet: http://www.analogmicro.de

Email:

info@analogmicro.de

BOUNDARY CONDITIONS

Parameter

Symbol

Conditions

Min.

Typ.

Max.

Unit

Sense Resistor

17

27

38

c

⋅ 17

c

⋅ 27

c

⋅ 38

Stabilization Resistor

R

35

40

45

R

c

⋅ 35

c

⋅ 40

c

⋅ 45

Load Resistance

Limitation only for 3-wire operation

0

600

Sum Gain Resistors

20

200

k

Sum Offset Resistors

20

200

k

Ceramic

1.9

2.2

5.0

µF

Output Capacitance

Only for 2-wire operation

90

100

250

nF

35

50

V

F

BCX54/55/56, for example

50

150

DETAILED DESCRIPTION OF FUNCTIONS

AM462 is a modular, universal V/I converter and protector IC which has been specially developed

for the conditioning of voltage signals referenced to ground. It is designed for both 2- and 3-wire

operation in industrial applications (cf. application in Figure 8). AM462’s various functions are

depicted in the block diagram (Figure 2) which also illustrates how few external components are

required for the operation of this particular device.

AM462 consists of several modular function blocks (operational amplifiers, voltage-to-current

converters and references) which, depending on external configurations, can either be switched to

one another or operated separately (see the basic circuitry in Figure 2):

1. Operational amplifier stage OP1 enables a positive voltage signal to be amplified. OP1 gain

integrated into the chip, limiting the voltage to the set value of the reference voltage. Output

GAIN

INP

OUTAD

G

V

V

⋅

=

with

2

1

1

R

R

G

GAIN

+

=

(1)

2. The internal voltage-to-current converter (V/I converter) provides a voltage-controlled current

output current to be finely adjusted with parallel operation of current and the voltage output. For