AD AD8628

PRELIMINARY TECHNICAL DATA
Zero-Drift, Single-Supply,
Rail-to-Rail Input/Output
Low Noise Operational Amplifier
a
AD8628
Preliminary Technical Data
the AD8628 family to reduce input biasing complexity and
maximize SNR.
FEATURES
Lowest auto-zero amplifier noise
Low Offset Voltage: 5 µV
Input Offset Drift: 0.03 µV/°C
Rail-to-Rail Input and Output Swing
5 V Single-Supply Operation
High Gain, CMRR, and PSRR: 120 dB
Very Low Input Bias Current: 100 pA
Low Supply Current: 1.3 mA
Overload Recovery Time: 0.2 ms
No External Components Required
The AD8628 family is specified for the extended industrial
(-40° to +125°C) temperature range. The AD8628 amplifier is
available in the tiny SOT23 and the popular 8-pin narrow
SOIC plastic packages.
5-Lead SOT
(RT-5)
AD8628
APPLICATIONS
Automotive Sensors
Pressure and Position Sensors
Strain Gage Amplifiers
Medical Instrumentation
Thermocouple Amplifiers
8-Lead SO
(R-8)
GENERAL DESCRIPTION
AD8628
This new family of amplifiers has ultra-low offset, drift and bias
current. The AD8628 is a wide bandwidth auto-zero amplifier
featuring rail-to-rail input and output swings and low noise.
Operation is fully specified from 2.7 to 5 volts single supply
(±1.35V to ±2.5V dual supply).
The AD8628 family provides the benefits previously found only
in expensive auto-zeroing or chopper-stabilized amplifiers.
Using Analog Devices’ new topology these zero-drift amplifiers
combine low cost, with high accuracy and low noise. (No
external capacitors are required.) In addition, the AD8628
greatly reduces the digital switching noise found in most
chopper stabilized amplifiers.
With an offset voltage of only 1µV, drift less than 0.005 µV/°C
and noise of only 0.5uV P-P (0Hz to 10 Hz) the AD8628 is
perfectly suited for applications where error sources cannot be
tolerated. Position and pressure sensors, medical equipment, and
strain gage amplifiers benefit greatly from nearly zero drift over
their operating temperature range. Many systems may take
advantage of the rail-to-rail input and output swings provided by
Specifications
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 which may result from its
use. No license is granted by implication or otherwise under any patent or patent
rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
World Wide Web Site: http://www.analog.com
Tel: 617/329-4700
© Analog Devices, Inc., 2002
Fax: 617/326-8703
PRELIMINARY TECHNICAL DATA
AD8628
ELECTRICAL SPECIFICATIONS (@ VS=+5.0V, VCM = +2.5V, VO=+2.5V, TA=+25°C unless otherwise specified.)
Parameter
Symbol
INPUT CHARACTERISTICS
Offset Voltage
VOS
Conditions
Min
Typ
IB
Input Offset Current
IOS
5
µV
30
10
100
µV
pA
50
1.5
200
nA
pA
250
5
pA
V
dB
-40°C ≤ TA ≤ +125°C
-40°C ≤ TA ≤ +125°C
Input Voltage Range
Common-Mode Rejection Ratio
CMRR
VCM = 0V to 5V
-40°C ≤ TA ≤ +125°C
115
130
dB
Large Signal Voltage Gain (Note 1)
AVO
RL = 10 kΩ, Vo=0.3 to 4.7V
125
145
dB
-40°C ≤ TA ≤ +125°C
120
Offset Voltage Drift
∆VOS/∆T
OUTPUT CHARACTERISTICS
Output Voltage High
VOH
Output Voltage Low
VOL
0
120
Units
1
-40°C ≤ TA ≤ +125°C
Input Bias Current
Max
-40°C ≤ TA ≤ +125°C
Output Current
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Overload Recovery Time
Gain Bandwidth Product
NOISE PERFORMANCE
Voltage Noise
Voltage Noise
Voltage Noise Density
Current Noise Density
135
0.002
dB
0.03
µV/°C
RL = 100kΩ to Ground
4.99
4.996
V
-40°C ≤ TA ≤ +125°C
4.99
4.995
V
V
RL = 10kΩ to Ground
4.95
4.98
-40°C ≤ TA ≤ +125°C
4.95
4.97
RL = 100kΩ to V+
V
1
10
mV
-40°C ≤ TA ≤ +125°C
2
10
mV
RL = 10 kΩ to V+
10
20
mV
15
± 50
20
mV
mA
-40°C ≤ TA ≤ +125°C
Short Circuit Limit
140
ISC
± 25
-40°C ≤ TA ≤ +125°C
± 40
± 30
mA
mA
-40°C ≤ TA ≤ +125°C
± 15
mA
dB
IO
PSRR
VS = 2.7V to 5.5V
120
130
115
ISY
-40°C ≤ TA ≤ +125°C
VO = 0V
130
1.3
1.5
dB
mA
-40°C ≤ TA ≤ +125°C
1.6
1.8
mA
RL =10 kΩ
0.8
0.05
2.5
0.2
V/µs
ms
MHz
SR
GBP
en p-p
en p-p
0.1 to 10 Hz
0.1 to 1.0 Hz
en
in
f = 1 kHz
f=10 Hz
0.5
0.16
22
5
µVp-p
µVp-p
nV/√Hz
fA/√Hz
Note 1: Gain testing is highly dependent upon test bandwidth.
–2–
REV. PrA
1/29/02
PRELIMINARY TECHNICAL DATA
AD8628
ELECTRICAL SPECIFICATIONS (@ VS=+2.7V, VCM = +1.35 V, VO=1.4V, TA=+25°C unless otherwise specified.)
Parameter
Symbol
INPUT CHARACTERISTICS
Offset Voltage
AD8628
VOS
Conditions
Min
Typ
IB
Input Offset Current
IOS
-40°C ≤ TA ≤ +125°C
5
µV
30
10
100
µV
pA
1.0
50
1.5
200
nA
pA
250
5
pA
V
dB
-40°C ≤ TA ≤ +125°C
Input Voltage Range
Common-Mode Rejection Ratio
CMRR
VCM = 0 to 2.9V
-40°C ≤ TA ≤ +125°C
110
120
dB
Large Signal Voltage Gain
AVO
RL = 10 kΩ, Vo=0.3 to 4.7V
110
140
dB
-40°C ≤ TA ≤ +125°C
105
Offset Voltage Drift
∆VOS/∆T
OUTPUT CHARACTERISTICS
Output Voltage High
VOH
Output Voltage Low
VOL
0
115
Units
1
-40°C ≤ TA ≤ +125°C
Input Bias Current
Max
-40°C ≤ TA ≤ +125°C
Output Current
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Overload Recovery Time
Gain Bandwidth Product
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Current Noise Density
Specifications
130
0.002
dB
0.03
µV/°C
RL = 100kΩ to Ground
2.68
2.695
V
-40°C ≤ TA ≤ +125°C
2.68
2.695
V
V
RL = 10kΩ to Ground
2.67
2.68
-40°C ≤ TA ≤ +125°C
2.67
2.675
RL = 100kΩ to V+
V
1
10
mV
-40°C ≤ TA ≤ +125°C
2
10
mV
RL = 10 kΩ to V+
10
20
mV
15
± 15
20
mV
mA
-40°C ≤ TA ≤ +125°C
Short Circuit Limit
130
ISC
±10
-40°C ≤ TA ≤ +125°C
± 10
± 10
mA
mA
-40°C ≤ TA ≤ +125°C
±5
mA
dB
IO
PSRR
VS = 2.7V to 5.5 V
120
130
115
ISY
-40°C ≤ TA ≤ +125°C
VO = 0V
130
1.1
1.4
dB
mA
-40°C ≤ TA ≤ +125°C
1.3
1.6
mA
RL =10 kΩ
1
0.05
2
V/µs
ms
MHz
en p-p
0.1 to 10 Hz
0.75
µVp-p
en
in
f = 1 kHz
f=10 Hz
SR
GBP
–3–
33
5
nV/√Hz
fA/√Hz
PRELIMINARY TECHNICAL DATA
AD8628
ABSOLUTE MAXIMUM RATINGS
Supply Voltage ..........................................................................+6V
Input Voltage......................................................GND to Vs + 0.3V
Differential Input Voltage1 .....................................................±5.0V
Output Short-Circuit Duration to Gnd...............................Indefinite
Storage Temperature Range
RT, R Package ............................................... -65°C to +150°C
Operating Temperature Range
AD8628 ......................................................... -40°C to +125°C
Junction Temperature Range
RT, R Package ............................................... -65°C to +150°C
Lead Temperature Range (Soldering, 10 sec).......................+300°C
Package Type
θJA2
θJC
Units
5-Pin SOT23 (RT)
8-Pin SOIC (R)
158
43
°C/W
°C/W
NOTES
1 Differential input voltage is limited to ±5.0 volts or the supply voltage, whichever is less.
2 θ is specified for the worst case conditions, i.e., θ is specified for device in socket
JA
JA
for P-DIP packages; θJAis specified for device soldered in circuit board for SOIC and
TSSOP packages.
ORDERING GUIDE
–4–
Model
Temperature
Range
Package
Description
Package
Option
AD8628ART
AD8628AR
-40°C to +125°C
-40°C to +125°C
5-Pin SOT23
8-Pin SOIC
RT-5
SO-8
REV. PrA
1/29/02