High Precision Instrumentation Amplifier AM447
analog microelectronics April 2000
Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 1/6
An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev. 2.1
Internet: www.analogmicro.de E–Mail: info@analogmicro.de
FEATURES
• Very Low Offset Voltage: < 25µV
• Low Input Bias Current: ≤ 5nA
• High Input Sensitivity
• High CMRR: > 90dB min
• Wide Operating Temperature Range:
–40°C...+140°C
• Adjustable Rail–to–Rail Voltage Out-
put Stage: 0.5...4.5V
• Single Supply Device (ratiometric)
• Integrated Source and Sink Capabil-
ity: ±2mA
• Low Noise Behaviour
APPLICATIONS
• Small Signal (Bridge) Amplifier
Low Pressure Sensors
Automotive Applications
DMS Interface
Interface for Ceramic Sensors
• High Precision Amplifier
Medical Instrumentation
Data Acquisition
GENERAL DESCRIPTION
The AM447 is a high precision amplifier, de-
signed for amplification of sensor bridge sig-
nals up to 35mV full scale. The single supply
circuit consists of a high precision instrumen-
tation amplifier (IA) and an integrated ra-
tiometric output stage. Input offset voltages
less than ±25µV (±1µV/°C) are adjustable by
only two externally trimmable resistors. The
monitoring of the amplified signal is possible
at the output of the IA and makes the adjust-
ment easier. With the externally adjustable
gain of the output stage, the AM447 can be
used for different signal sources. The 2mA
sink and source capability makes it ideal for
high precision applications specially in the
field of automotive sensors.
DELIVERY
• DIL16 packages (samples, small quantities)
• SO16(n) packages
• Dice on 5“ blue foil
BLOCK DIAGRAM
1k
4
AM447
IA
Output
Stage
10
11
6
7
1412
5 8
3
OC2OC1
IN-
IN+
VCC
OUT
GAIN
GNDIAOUTVREFVREFINRSET
12
VSET
9
V
CC
19k
Figure 1