AD629 Datasheet, PDF (1/12 Pages) Analog Devices – High Common-Mode Voltage Difference Amplifier

a
FEATURES
Improved Replacement for:
INA117P and INA117KU
؎270 V Common-Mode Voltage Range
Input Protection to:
؎500 V Common Mode
؎500 V Differential
Wide Power Supply Range (؎2.5 V to ؎18 V)
؎10 V Output Swing on ؎12 V Supply
1 mA Max Power Supply Current
HIGH ACCURACY DC PERFORMANCE
3 ppm Max Gain Nonlinearity
20 ␮V/؇C Max Offset Drift (AD629A)
10 ␮V/؇C Max Offset Drift (AD629B)
10 ppm/؇C Max Gain Drift
EXCELLENT AC SPECIFICATIONS
77 dB Min CMRR @ 500 Hz (AD629A)
86 dB Min CMRR @ 500 Hz (AD629B)
500 kHz Bandwidth
APPLICATIONS
High Voltage Current Sensing
Battery Cell Voltage Monitor
Power Supply Current Monitor
Motor Control
Isolation
100
95
90
85
80
75
70
65
60
55
50
20
100
1k
FREQUENCY – Hz
10k 20k
Figure 1. Common-Mode Rejection Ratio vs. Frequency
High Common-Mode Voltage
Difference Amplifier
AD629
FUNCTIONAL BLOCK DIAGRAM
8-Lead Plastic Mini-DIP (N) and SOIC (R) Packages
21.1k⍀ 380k⍀
REF(–) 1
380k⍀
–IN 2
380k⍀
+IN 3
–V_S 4
20k⍀
AD629
NC = NO CONNECT
8 NC
7 +V_S
6 OUTPUT
5 REF(+)
GENERAL DESCRIPTION
The AD629 is a difference amplifier with a very high input
common-mode voltage range. It is a precision device that
allows the user to accurately measure differential signals in the
presence of high common-mode voltages up to ± 270 V.
The AD629 can replace costly isolation amplifiers in applications
that do not require galvanic isolation. The device will operate
over a ±270 V common-mode voltage range and has inputs
that are protected from common-mode or differential mode
transients up to ± 500 V.
The AD629 has low offset, low offset drift, low gain error drift,
as well as low common-mode rejection drift, and excellent CMRR
over a wide frequency range.
The AD629 is available in low-cost, plastic 8-lead DIP and
SOIC packages. For all packages and grades, performance is
guaranteed over the entire industrial temperature range from
–40°C to +85°C.
2mV/DIV
60V/DIV
–240
–120
0
120
240
COMMON-MODE VOLTAGE – Volts
Figure 2. Common-Mode Operating Range. Error Voltage
vs. Input Common-Mode Voltage
REV. A
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© Analog Devices, Inc., 2000