UNIVERSAL AMPLIFIER IC

AM400

analog microelectronics

October 2005

Analog Microelectronics GmbH

Phone:

+49 (0)6131/91 073 – 0

7/21

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

BOUNDARY CONDITIONS

Parameter

Symbol

Conditions

Min.

Typ.

Max.

Unit

Sense Resistor

17

27

38

Ω

c

⋅ 17

c

⋅ 27

c

⋅ 38

Ω

Stabilization Resistor

35

40

45

Ω

c

⋅ 35

c

⋅ 40

c

⋅ 45

Ω

Load Resistance

Limitation only for 3-wire operation

0

600

Ω

Sum Gain Resistors

20

200

k

Ω

Sum Offset Resistors

20

200

k

Ω

1.9

2.2

5.0

µF

Output Capacitance

Only for 2-wire operation

90

100

250

nF

35

50

V

BCX54/55/56, for example

50

150

DETAILED DESCRIPTION OF FUNCTIONS

AM462 is a modular, monolithically integrated universal amplifier which has been specifically

developed for the conditioning of differential voltage signals and those referenced to ground. It is

until 19). AM462’s various functions are depicted in the block diagram (Figure 1) which also

illustrates how few external components are required for the operation of this particular device.

AM400 consists of a number of modular functional blocks which through external gating can either

operate together or separately (see Figure 2).

differential voltage signals. Its special construction permits a high common mode rejection ratio

(CMRR). The amplifier reference potential is set externally using the AM400 pin ZA. Output

ZA

IN

IA

OUTIA

V

V

G

V

+

=

with

0

>

OUTIA

V

(1)

voltage at pin ZA.

2. The ensuing operational amplifier stage (OP1) permits the IA output signal to be amplified

overvoltage has been integrated into the device; this protective circuitry limits the voltage to the

set reference voltage value (cf. paragraph 5 in this section).