廬
APPLICATION BULLETIN
Mailing Address: PO Box 11400 鈥?Tucson, AZ 85734 鈥?Street Address: 6730 S. Tucson Blvd. 鈥?Tucson, AZ 85706
Tel: (602) 746-1111 鈥?Twx: 910-952-111 鈥?Telex: 066-6491 鈥?FAX (602) 889-1510 鈥?Immediate Product Info: (800) 548-6132
SINGLE-SUPPLY, LOW-POWER
MEASUREMENTS OF BRIDGE NETWORKS
By Bonnie Baker (602) 746-7984
Bridge sensor measurements often need to be made in
systems operating on a single 5V power supply. An OPA1013
dual op amp along with a REF200 current source, makes an
excellent bridge measurement system which features low
power single-supply 5V operation and immunity to power
supply variations. One OPA1013 dual op amp is used as a
two-op-amp instrumentation amplifier. A second OPA1013
is used with a REF200 to make two voltage references. One
voltage reference is used to power the bridge, the other is
used to offset the instrumentation amplifier.
In Figure 1, A
1
and A
2
(an OPA1013 dual operational
amplifier) along with one of the current sources from the
REF200 establishes a 3.4V voltage reference for excitation
of a pressure transducer bridge. Although the REF200 con-
tains two current sources, the second current source is not
used, which keeps power consumption low.
A second OPA1013 (A
3
, A
4
), connected as a two op amp
instrumentation amplifier, amplifies the differential voltage
output from the bridge. Gain is easily adjusted with R
T
. If
1% resistors are used for R
4
-R
7
, common-mode rejection
will be better than 80dB for gains greater than 200V/V. A
CMR of 80dB is quite acceptable in this application.
The instrumentation amplifier鈥檚 reference connection is made
to a 0.5V reference at the output of A
2
. This voltage sets an
instrumentation amplifier offset so that a zero bridge output
will result in a 0.5V instrumentation amplifier output. The
value of the offset can be changed by adjusting R
3
.
V+ (4.5V to 36V)
1 2
REF200
100碌A(chǔ)
R
4
A
2
V
REF2
0.5V
10k鈩?1%
R
2
5.8k鈩?/div>
1 2
OPA1013
R
T
85鈩?/div>
R
1
1k鈩?/div>
A
1
1 2
OPA1013
V
REF1
3.4V
Bridge
Sensor
(1)
4k鈩?/div>
4k鈩?/div>
A
3
鈥?/div>
V
IN
4k鈩?/div>
4k鈩?/div>
+
A
4
1 2
OPA1013
1 2
OPA1013
R
5
10k鈩?1%
R
6
10k鈩?1%
R
7
10k鈩?1%
R
3
5k鈩?/div>
0.5V
V
OUT
NOTE: (1) Bridge sensor: SenSym part number BP101.
FIGURE 1. Single-Supply Bridge Measurement Circuit.
漏
1991 Burr-Brown Corporation
AB-033A
Printed in U.S.A. April, 1993
AB-033相關(guān)型號(hào)PDF文件下載
-
型號(hào)
版本
描述
廠商
下載
-
英文版
AB-001 - INCREASING INA117 DIFFERENTIAL INPUT RANGE
ETC
-
英文版
AB-002 - MAKE A PRECISION CURRENT SOURCE OR CURRENT SINK
ETC
-
英文版
AB-003 - VOLTAGE-REFERENCE FILTERS
ETC
-
英文版
AB-004 - MAKE A PRECISION -10V REFERENCE
ETC
-
英文版
AB-005 - Make A Precision -10V Reference
ETC
-
英文版
AB-006 - Make a -10V to +10V Adjustable Precision Voltage So...
ETC
-
英文版
AB-007 - CLASSICAL OP AMP OR CURRENT-FEEDBACK OP AMP?
ETC
-
英文版
AB-008 - AC COUPLING INSTRUMENTATION AND DIFFERENCE AMPLIFIE...
ETC
-
英文版
AB-009 - SINGLE-SUPPLY OPERATION OF ISOLATION AMPLIFIERS
ETC
-
英文版
AB-010 - -200V DIFFERENCE AMPLIFIER WITH COMMON-MODE VOLTAGE...
ETC
-
英文版
AB-011 - LOW POWER SUPPLY VOLTAGE OPERATION OF REF102 10.0V ...
ETC
-
英文版
AB-012 - BOOST ISO120 BANDWIDTH TO MORE THAN 100kHz
ETC
-
英文版
AB-013 - INCREASING ADC603 INPUT RANGE
ETC
-
英文版
AB-014 - INPUT OVERLOAD PROTECTION FOR THE RCV420 4-20mA CUR...
ETC
-
英文版
AB-015 - EXTENDING THE COMMON-MODE RANGE OF DIFFERENCE AMPLI...
ETC
-
英文版
AB-016 - BOOST AMPLIFIER OUTPUT SWING WITH SIMPLE MODIFICATI...
ETC
-
英文版
AB-017 - Sallen-Key Low-Pass Filter Design Program
ETC
-
英文版
AB-018 - 0 TO 20mA RECEIVER USING RCV420
ETC
-
英文版
AB-019 - USING THE ADS7800 12 BIT ADC WITH UNIPOLAR INPUT SI...
ETC
-
英文版
AB-020 - BURR-BROWN SPICE BASED MACROMODELS. REV. F
ETC
1
2
