INDUSTRIAL VOLTAGE AMPLIFIER IC

AM401

analog microelectronics

Mars 2006

Analog Microelectronics GmbH

Phone:

+49 (0)6131/91 073 – 0

11/21

An der Fahrt 13, D – 55124 Mainz

Fax:

+49 (0)6131/91 073 – 30

Rev. 2.3

Internet: http://www.analogmicro.de

Email:

info@analogmicro.de

APPLICATIONS

Application 1 – Differential input signal, voltage output signal of 0...5/10V

With applications which require an output voltage of 0...5/10V the pin used to configure the

instrumentation amplifier offset (ZA) is connected to the IC’s Ground. Gain G is set using the two

external resistors R1 and R2:

()

2

1

1

R

R

G

G

G

G

IA

OP

IA

+

=

=

(2)

If no offset voltage is present, the transfer function of the output voltage (Gl.1) is:

VOUT = G VIN

Using these equations the values of resistors R1 and R2 can be set as follows:

R

R

V

GV

OUT

IA

IN

1

2

1

=−

Example 1:

Input voltage (differential) of 0...50mV and output voltage range of 0...10V

If VIN = 0...50mV, R1/R2 = 39 and IREF ≥ 1mA the values of the external components are as follows:

R1 ≈ 117kΩ

R2 ≈ 3kΩ

GIA = 5

C1 = 2.2µF

C2 = 10nF

Example 2:

Input voltage (differential) of 0...100mV and output voltage range of 0...5V

If VIN = 0...100mV, R1/R2 = 9 and IREF ≥ 1mA the values of the external components are as follows:

R1 ≈ 90kΩ

R2 ≈ 10kΩ

GIA = 5

C1 = 2.2µF

C2 = 10nF