AD628
器件描述：High Common-Mode Voltage Programmable Gain Difference Amplifier
器件厂商：AD [Analog Devices]
文件大小：247.34KB，共20页
Sponsor by e络盟器件资料摘要：
High Common-Mode Voltage
Programmable Gain Difference Amplifier
AD628
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
FEATURES
High common-mode input voltage range
±120 V at VS = ±15 V
Gain range 0.1 to 100
Operating temperature range: −40°C to ±85°C
Supply voltage range
Dual supply: ±2.25 V to ±18 V
Single supply: 4.5 V to 36 V
Excellent ac and dc performance
Offset temperature stability RTI: 10 µV/°C max
Offset: ±1.5 V mV max
CMRR RTI: 75 dB min, dc to 500 Hz, G = +1
APPLICATIONS
High voltage current shunt sensing
Programmable logic controllers
Analog input front end signal conditioning
+5 V, +10 V, ±5 V, ±10 V and 4 to 20 mA
Isolation
Sensor signal conditioning
Power supply monitoring
Electrohydraulic control
Motor control
GENERAL DESCRIPTION
The AD628 is a precision difference amplifier that combines
excellent dc performance with high common-mode rejection
over a wide range of frequencies. When used to scale high
voltages, it allows simple conversion of standard control
voltages or currents for use with single-supply ADCs. A
wideband feedback loop minimizes distortion effects due to
capacitor charging of ∑-∆ ADCs.
A reference pin (VREF) provides a dc offset for converting
bipolar to single-sided signals. The AD628 converts +5 V, +10 V,
±5 V, ±10 V, and 4 to 20 mA input signals to a single-ended
output within the input range of single-supply ADCs.
The AD628 has an input common-mode and differential
mode operating range of ±120 V. The high common-mode
input impedance makes the device well suited for high voltage
measurements across a shunt resistor. The buffer amplifier’s
inverting input is available for making a remote Kelvin
connection.
FUNCTIONAL BLOCK DIAGRAM
R
EXT1
R
EXT2
R
G
+V
S
+IN
–IN
+IN
–IN
–V
S
A2
A1
+IN
–IN
100kΩ
100kΩ 10kΩ
10kΩ
V
REF
10kΩ
AD628
OUT
G = +0.1
C
FILT
02992-C
-
001
Figure 1.
30
40
50
60
70
80
90
100
110
120
130
CMRR (dB)
FREQUENCY (Hz)
10010 1k 10k 100k
02992-C-002
V
S
= ±2.5V
V
S
= ±15V
Figure 2. CMRR vs. Frequency of the AD628
A precision 10 kΩ resistor connected to an external pin is
provided for either a low-pass filter or to attenuate large
differential input signals. A single capacitor implements a low-
pass filter. The AD628 operates from single and dual supplies and
is available in an 8-lead SOIC or MSOP package. It operates over
the standard industrial temperature range of −40°C to +85°C.
Programmable Gain Difference Amplifier
AD628
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
FEATURES
High common-mode input voltage range
±120 V at VS = ±15 V
Gain range 0.1 to 100
Operating temperature range: −40°C to ±85°C
Supply voltage range
Dual supply: ±2.25 V to ±18 V
Single supply: 4.5 V to 36 V
Excellent ac and dc performance
Offset temperature stability RTI: 10 µV/°C max
Offset: ±1.5 V mV max
CMRR RTI: 75 dB min, dc to 500 Hz, G = +1
APPLICATIONS
High voltage current shunt sensing
Programmable logic controllers
Analog input front end signal conditioning
+5 V, +10 V, ±5 V, ±10 V and 4 to 20 mA
Isolation
Sensor signal conditioning
Power supply monitoring
Electrohydraulic control
Motor control
GENERAL DESCRIPTION
The AD628 is a precision difference amplifier that combines
excellent dc performance with high common-mode rejection
over a wide range of frequencies. When used to scale high
voltages, it allows simple conversion of standard control
voltages or currents for use with single-supply ADCs. A
wideband feedback loop minimizes distortion effects due to
capacitor charging of ∑-∆ ADCs.
A reference pin (VREF) provides a dc offset for converting
bipolar to single-sided signals. The AD628 converts +5 V, +10 V,
±5 V, ±10 V, and 4 to 20 mA input signals to a single-ended
output within the input range of single-supply ADCs.
The AD628 has an input common-mode and differential
mode operating range of ±120 V. The high common-mode
input impedance makes the device well suited for high voltage
measurements across a shunt resistor. The buffer amplifier’s
inverting input is available for making a remote Kelvin
connection.
FUNCTIONAL BLOCK DIAGRAM
R
EXT1
R
EXT2
R
G
+V
S
+IN
–IN
+IN
–IN
–V
S
A2
A1
+IN
–IN
100kΩ
100kΩ 10kΩ
10kΩ
V
REF
10kΩ
AD628
OUT
G = +0.1
C
FILT
02992-C
-
001
Figure 1.
30
40
50
60
70
80
90
100
110
120
130
CMRR (dB)
FREQUENCY (Hz)
10010 1k 10k 100k
02992-C-002
V
S
= ±2.5V
V
S
= ±15V
Figure 2. CMRR vs. Frequency of the AD628
A precision 10 kΩ resistor connected to an external pin is
provided for either a low-pass filter or to attenuate large
differential input signals. A single capacitor implements a low-
pass filter. The AD628 operates from single and dual supplies and
is available in an 8-lead SOIC or MSOP package. It operates over
the standard industrial temperature range of −40°C to +85°C.