PRELIMINARY TECHNICAL DATA
a
High Common-Mode Voltage
Programmable Gain Difference
Amplifier
Preliminary Technical Data
FEATURES:
High Common Mode Input Voltage Range
±100V
Gain Range 0.1 to 10,000
Operating Temperature Range:
8 Pin SOIC: –40°C to 85°C
Supply Voltage Range:
Dual Supply ±5V to ±18V
Single Supply 5V to 36V
EXCELLENT AC and DC PERFORMANCE
Offset Temperature Stability
1 µV/°C Max
Gain Drift
10 ppm/°C Max
CMRR
80 dB Min., DC to 500 Hz
AD628
FUNCTIONAL BLOCK DIAGRAM
8 Lead Plastic Mini-DIP (N) and SOIC (R) Packages
+VS
7
100k Ω
+IN
10k Ω
1
AD628
G = 0.1
-IN
-IN
8
100k Ω
A1
+IN
10k Ω
OUT
+IN
A2
5
-IN
10k Ω
3
2
VREF
-VS
4
CFILT
6
RG
APPLICATIONS
Programmable Logic Controllers
Analog Input Front End:
5V, 10V, ±5V, ±10V and 4 to 20mA
High Voltage Current Sensing
Isolation
Sensor Signal Conditioning
GENERAL DESCRIPTION
The AD628 is a precision difference amplifier with
excellent DC specifications and high common mode
rejection ratio over frequency. It allows the user to
attenuate industry standard analog input voltages
or currents to the acceptable input voltage range of
the new generation of analog to digital and sigma
delta converters. The REF also provides an offset to
convert a bipolar input signal to a unipolar output.
So, the AD628 converts 5V, 10V, ±5V, ±10V and 4 to
20mA input signals to a single ended output that is
within the input range of single supply A/D
converters and sigma delta converters.
The AD628 has an input common mode and
differential mode operating range of ±100V. The
high common mode input impedance makes the
device well suited for high voltage measurements
across a shunt resistor.
The AD628 operates on both single and dual
supplies. The device also allows the user to set a
single pole, using an external capacitor on the VCOMP
pin, to filter out noise.
REV. PrA 4/26/2002
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
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106,
U.S.A.
may result from its use.
No license is granted by implication of otherwise
Tel: 781/329-4700
www.analog.com
under any patent or patent rights of Analog Devices.
Fax: 781/326-8703
Analog Devices, Inc., 2002
PRELIMINARY TECHINCAL DATA
The AD628 is available in both an 8-Pin Dip and
SOIC packages and is specified over the standard
industrial temperature range, -40°C to 85°C.
-24/26/2002 REV. PrA
PRELIMINARY TECHINCAL DATA
AD628 - SPECIFICATIONS
Parameter
GAIN
Gain Equation
Conditions
Min
G= 0.1 (1+ REXT1/REXT2)
REXT1= 100kΩ; REXT2= ∝ Ω
VOUT= ±10V; RL = 2kΩ
Max
0.1
Gain Error
Gain Nonlinearity
±Gain vs. Temperature
VOLTAGE OFFSET
Offset Voltage (RTI)
Offset Voltage (RTI)
VS. Temperature
VS. Supply
Typ
V/V
.01
0.05
3
20
10
ppm
ppm/°C
0.1
0.2
1
mV
mV
µV/°C
dB
VS = ±5V to ±15V
VS = 5V
100
INPUT
Input Operating Impedance
Differential
Common Mode
Input Operating Voltage Range
Common Mode
Differential
Common Mode Rejection Ratio
TA = Tmin to Tmax
F = 500Hz
Unit
%
220
55
kΩ
kΩ
±100
±100
V
V
80
76
80
dB
dB
dB
±12.5V
±13V
±4V
1
4
V
V
V
V
100
10
µV
nA
OUTPUT
Operating Voltage Range
VS = ±15V; RL = 2kΩ
VS = ±15V; RL = 10kΩ
VS = ±5V; RL = 10kΩ
VS = 5V; RL = 10kΩ
OUTPUT BUFFER
Offset Voltage
Input Bias Current
DYNAMIC RESPONSE
Small Signal -3dB Bandwidth
Full Power Bandwidth
Settling Time
Slew Rate
500
3
kHz
kHz
0.3
V/µS
2
70
µV p-p
nV/√Hz
NOISE
0.01 Hz to 10 Hz
Spectral Density, 1 kHz
POWER SUPPLY
Operating Range
Quiescent Current
TEMPERATURE RANGE
For Specified Performance
5
±15
1.5
V
mA
-40
+85
°C
-34/26/2002 REV. PrA