Industrial V/I Converter and Protector IC

AM462

Analog Microelectronics GmbH

An der Fahrt 13, D – 55124 Mainz

Oktober 2007 – Rev.2.5 -Page 7/20

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

Fax: +49 (0)6131/91 073-30

Internet:

http://www.analogmicro.de

Email: info@analogmicro.de

SET

IV

INDAI

OUT

I

R

G

V

I

+

⋅

=

0

=

SET

INDAI

I

R

V

+

0

8

with

0

2R

V

I

SET

SET =

(2)

with VINDAI the voltage at pin 6 (INDAI) and VSET the voltage at pin 16 (SET)

1.

3. The AM462 reference voltage source enables voltage to be supplied to external components

(such as sensors, microprocessors, etc.). The reference voltage value VREF can be set via pin 13

VSET. If pin VSET is not connected, VREF = 5V; if VSET is switched to ground, VREF = 10V.

Values between the above can be set if two external resistors are used (inserted between pin

VREF and pin VSET and between pin VSET and GND; see Figure 2).

External (ceramic) capacitor C1 at pin VREF stabilizes the reference voltage. It must be

connected even if the voltage reference is not in use.

4. The additional operational amplifier stage OP2 can be used as a current or voltage source to

supply external components. OP2's positive input is connected internally to voltage VBG so that

the output current or output voltage can be set across a wide range using external resistors.

1 The construction of the V/I converter is such that output current IOUT is largely independent of the current

amplification

βF of external transistor T1. Production-specific variations in the current amplification of the transistors

used are compensated for internally by the V/I converter.

V

BG

Ground

V

S

I

OUT

R

1

R

2

R

0

T

1

D

1

R

5

V

INP

V

SET

V

OUTAD

V

CVREF

V

CVSET

R

4

V

BG

4

11

10

8

OP1

5

2

AM462

OP2

3

C

1

V

REF

R

3

13

15

Voltage Reference

1

16

9

V

INDAI

14

V

I

6

Figure 2: Block diagram of AM462 (3-wire circuit for current output). Pin 1 and 2

have to be connected.