AM417 – Ratiometric instrumentation

amplifier with adjustable output stage

Analog Microelectronics GmbH

An der Fahrt 13, D – 55124 Mainz

July 2008 –Rev 3.1- Page 13/18

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

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

Email: info@analogmicro.de

and from Equation 11 we are presented with:

mV

mV

mV

V

V

RO

5

.

6

6

2

67

.

6

10

5

.

0

2

−

=













−

−

⋅

⋅

=

Referring to Equation 12a the resistance for offset calibration is thus:

()

Ω

=

⋅

−

⋅

=

13

2

'

0

0

IB

R

I

V

R

TEMPERATURE COMPENSATION OF THE OUTPUT SPAN

Supplying a piezoresistive sensing element with constant current makes compensation of the

temperature of the span a relatively simple affair. With a constant current supply the negative

temperature coefficient of sensor sensitivity S can be compensated by the positive temperature

2

I

IB

R

1

4

5

R

TSC

3

Input pin

AM417

I

IB

´

R

BR

Figure 4

: Bridge array for the compensation of TC with