參數(shù)資料
型號(hào): AD22050
廠商: Analog Devices, Inc.
英文描述: Single-Supply Sensor Interface Amplifier
中文描述: 單電源傳感器接口放大器
文件頁(yè)數(shù): 6/8頁(yè)
文件大?。?/td> 148K
代理商: AD22050
AD22050
–6–
REV. C
To produce a full-scale output of +4 V, a gain
×
40 is used, adjust-
able by
±
5% to absorb the tolerance in the sense resistor. There is
sufficient headroom to allow at least a 10% overrange (to +4.4 V).
The roughly triangular voltage across the sense resistor is aver-
aged by a single-pole low-pass filter, here set with a corner fre-
quency of f
C
= 3.6 Hz, which provides about 30 dB of attenuation
at 100 Hz. A higher rate of attenuation can be obtained by a
two-pole filter having f
C
= 20 Hz, as shown in Figure 11. Al-
though this circuit uses two separate capacitors, the total capaci-
tance is less than half that needed for the single-pole filter.
AD22050
–IN GND A1
+IN
OFS +V
S
OUT
A2
100m
V
SOLENOID
LOAD
POWER
DARLINGTON
CMOS DRIVER
+V
S
(BATTERY)
CHASSIS
C
432k
V
50k
V
+5V
ANALOG
OUTPUT
CORNER FREQUENCY
= 1Hz-
m
F
(0.05
m
F FOR f
C
= 20Hz)
ANALOG
COMMON
FLYBACK
DIODE
127k
V
C
Figure 11. Illustration of Two-Pole Low-Pass Filtering
STRAIN GAGE INTERFACE: MIDSCALE OFFSET
FEATURE
The AD22050 can be used to interface a strain gage to a subse-
quent process where only a single supply voltage is available. In
this application, the midscale offset feature is valuable, since the
output of the bridge may have either polarity. Figure 12 shows
typical connections.
AD22050
–IN GND A1
+IN
OFS +V
S
OUT
A2
R
L
10k
V
+V
S
ANALOG OUTPUT
ANALOG COMMON
100k
V
OS
NULL
OPTIONAL
LP FILTER
125k
V
(SETS GAIN
TO
3
100)
V
G
R
R
R
R
Figure 12. Typical Connections for a Strain Gage Interface
Using the Offset Feature
The offset is obtained by connecting Pin 7 (OFS) to the supply
voltage. In this way, the output of the AD22050 is centered to
midway between the supply and ground. In many systems the
supply will also serve as the reference voltage for a subsequent
A/D converter. Alternatively, Pin 7 may be tied to the reference
voltage from an independent source. The AD22050 is trimmed
to guarantee an accuracy of
±
2% on the 0.5 ratio between the
voltage on Pin 7 and the output.
An ac excitation of up to
±
2 V can also be used because the
common-mode range of the AD22050 extends to –1 V. Assum-
ing a full-scale bridge output (V
G
) of
±
10 mV, a gain of
×
100
might be used to provide an output of
±
1 V (a full-scale range
of +1.5 V to +3.5 V). This gain is achieved using the method
discussed in connection with Figure 5. Note that the gain-
setting resistor does not affect the accuracy of the midscale
offset. (However, if the gain were lowered, using a resistor to
ground, this offset would no longer be accurate.) A V
OS
nulling
pot is included for illustrative purposes. One-, two- and three-
pole filtering can also be implemented, as discussed in the
Low-Pass Filtering section.
Using the Midscale Offset Feature
Figure 13 shows a more detailed schematic of the output am-
plifier A2. Because this is a single supply device, the output
stage has no pull-down transistor. Such a transistor would limit
the minimum output to several hundred millivolts above
ground. When using the AD22050 in unipolar mode (Pin 7
grounded), the resistors making up the feedback network also
act as a pull-down for the output stage.
A2
10k
V
95k
V
+V
S
20k
V
OFS
OUT
20k
V
R
L
GND
Figure 13. Detailed Schematic of Output Amplifier A2
If the output is called upon to source current (not sink), then it
can swing almost completely to ground (within 20 mV). How-
ever, if the offset pin is connected to some positive voltage
source, this source will “pull up” the output voltage, thereby
limiting the minimum output swing. With no external load the
minimum output voltage possible is V
OFS
/2. For example, if Pin
7 is connected to +5 V, the minimum output voltage is equal
to the offset voltage of 2.5 V. By adding an additional load, as
shown, the output swing toward ground can be extended.
The relationship is described by:
V
OUT
>
1
2
V
OFS
R
L
R
L
+
20
k
*
*This 20 k
resistor is internal to the AD22050 and can vary by
±
30%.
where R
L
is an externally applied load resistor. However, R
L
cannot be made arbitrarily small since this would require exces-
sive current from the output. The output current should be
limited to 5 mA total.
相關(guān)PDF資料
PDF描述
AD22050R-REEL Single-Supply Sensor Interface Amplifier
AD22050N Single-Supply Sensor Interface Amplifier
AD22050R Single-Supply Sensor Interface Amplifier
AD22055 ECONOLINE: RD & RC - Dual Output from a Single Input Rail- 1kVDC & 2kVDC Isolation- Power Sharing on Output- Custom Solutions Available- UL94V-0 Package Material- Efficiency to 86%
AD22055N Single Supply Bridge Transducer Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD22050N 制造商:Analog Devices 功能描述:SP Amp DIFF AMP Single 36V 8-Pin PDIP Tube 制造商:Rochester Electronics LLC 功能描述:I.C. SENSOR INTERFACE IC - Bulk 制造商:Analog Devices 功能描述:SEMICONDUCTORS ((NW)) 制造商:Analog Devices 功能描述:Single-Supply Sensor Interface Amplifier 制造商:Analog Devices Inc. 功能描述:Single-Supply Sensor Interface Amplifier
AD22050NZ 功能描述:IC AMP DIFF SGL SUPPLY 8-DIP RoHS:是 類(lèi)別:集成電路 (IC) >> 接口 - 傳感器和探測(cè)器接口 系列:- 其它有關(guān)文件:Automotive Product Guide 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:74 系列:- 類(lèi)型:觸控式傳感器 輸入類(lèi)型:數(shù)字 輸出類(lèi)型:數(shù)字 接口:JTAG,串行 電流 - 電源:100µA 安裝類(lèi)型:表面貼裝 封裝/外殼:20-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:20-TSSOP 包裝:管件
AD22050R 制造商:Analog Devices 功能描述:SP Amp DIFF AMP Single 36V 8-Pin SOIC N Tube 制造商:Rochester Electronics LLC 功能描述:SENSOR INTERFACE IC - Bulk
AD22050R-REEL 制造商:Analog Devices 功能描述:SP Amp DIFF AMP Single 36V 8-Pin SOIC N T/R 制造商:Rochester Electronics LLC 功能描述:IC SENSOR IC - Tape and Reel
AD22050R-REEL7 制造商:Analog Devices 功能描述:SP Amp DIFF AMP Single 36V 8-Pin SOIC N T/R 制造商:Rochester Electronics LLC 功能描述:IC SENSOR IC - Tape and Reel