am457 AME, Inc., am457 Datasheet - Page 3

• Manufacturer Part Number: am457
• Description: Precision Amplifier For Bridge Circuits - Analog Microelectronics
• Manufacturer: AME, Inc.

Precision amplifier for bridge circuits
FEATURES
x High input sensitivity
x Wide differential input voltage range
x Low offset
x Low offset drift
x Low input noise
x High CMRR: > 120dB
x Wide operating temperature range:
x Adjustable output voltage
x Rail-to-rail output stage:
x Sink/source output
x Single ratiometric supply: V
x Integrated current source: d 2mA
x Integrated diagnostic unit
x Separate function groups
x Integrated EMV protective circuitry
x Short-circuit-proofing
x Small-scale design
BLOCK DIAGRAM
analog microelectronics
Analog Microelectronics GmbH
An der Fahrt 13, D – 55124 Mainz
Internet: www.analogmicro.de
Figure 1: Block diagram
OUTOP
INOP
(r5...r100mV FS)
-40... +125°C
V
IN+
OUT
_
7
6
= 0.2V ... V
AM457
AMP
cc
– 0.2V
OP
CC
= 5V
Temp
1k
Phone:
Fax:
Email:
Diagnostic
9k
unit
GND
4
+49 (0)6131/91 073 – 30
+49 (0)6131/91 073 – 0
[e-mail]
V
CC
GENERAL DESCRIPTION
AM457 is a high-precision integrated amplifier which
has been developed to condition signals from small
differential input voltages within a range of a few
millivolts (r5 to r100mV FS). The chief component
of the IC is a highly accurate, low-noise amplifier
circuit (AMP). An additional integrated operational
amplifier (OP) can be used to supply a sensing
element with current or record temperature for sensor
bridges powered by voltage, for example. The entire
system (sensing element plus amplifier) is monitored
by the integrated diagnostic unit which logs any
sensing
undervoltage,
temperature. The various function groups are not
mutually dependent on one another; the AMP can be
operated independently of the OP, for example. The
functionality of both component groups (AMP and
OP) is autonomous with regard to the diagnostic unit.
AM457 is a combination of high-impedance precision
amplifier, additional OP and extensive diagnostic unit,
enabling a self-monitoring sensor system to be
assembled using very few components.
5
8
1
VCC
DIAG
OUT
element
AMP
errors
overloads
or
defects,
and
AM457
May 2005
excessive
Rev. 2.2
system
3/10