19-0924; Rev 1; 4/09
KIT
ATION
EVALU
BLE
AVAILA
Ultra-Low Offset/Drift, Precision
Instrumentation Amplifiers with REF Buffer
General Description
Features
♦
Ultra-Low Input Offset Voltage
±20µV (max) at +25°C
♦
±0.25% (max) Gain Error
♦
Low 0.2µV/°C Offset Voltage Drift
♦
1pA CMOS Input Bias Current
♦
True Ground Sensing with Rail-to-Rail Output
♦
Buffered REF Input for High Accuracy and
Bipolar Operation
♦
2.85V to 5.5V Single-Supply Operation
(or ±1.425V to ±2.75V Dual Supplies)
♦
750µA Supply Current
♦
1.4µA Shutdown Mode
♦
750kHz Gain-Bandwidth Product
♦
Operate Over the -40°C to +125°C Automotive
Temperature Range
♦
Tiny 8-Pin
µMAX
Package
MAX4208/MAX4209
The MAX4208/MAX4209 ultra-low offset and drift instru-
mentation amplifiers feature exceptional precision specifi-
cations, low power consumption, rail-to-rail output,
excellent gain-bandwidth product, and buffered
REFIN/MODE input in a very small µMAX
®
package.
These devices use a spread-spectrum, autozeroing
technique that constantly measures and corrects the
input offset, eliminating drift over time and temperature and
the effect of 1/f noise. This technique achieves less than
20µV offset voltage, allows ground-sensing capability, pro-
vides ultra-low CMOS input bias current and increased
common-mode rejection performance.
The MAX4208/MAX4209 provide high-impedance inputs
optimized for small-signal differential voltages (±100mV).
All devices provide a gain-bandwidth product of 750kHz.
The MAX4208 provides an adjustable gain with two
external resistors or unity gain with FB connected to OUT.
The MAX4209 is available with a fixed gain of 100V/V with
±0.03% (typ) accuracy. Both devices include a reference
input (REF) to level-shift the output, allowing for bipolar
signals in single-supply applications. In both devices,
REFIN/MODE is an input to a precision unity-gain buffer,
which sets the REF voltage to level-shift the output. The
internal REF buffer allows the reference to be set by a
simple resistive divider or an ADC reference without any
loading error.
The MAX4208/MAX4209 operate with a 2.85V to 5.5V
single-supply voltage and consume only 750µA
of quiescent current (when the internal buffer is off) and
only 1.4µA in shutdown mode. These amplifiers
also operate with ±2.5V dual supplies with REF
connected to ground and REFIN/MODE to V
SS
.
The MAX4208/MAX4209 are available in space-saving
8-pin µMAX packages and are specified over the auto-
motive operating temperature range (-40°C to +125°C).
Ordering Information
PART
MAX4208AUA+T
MAX4209HAUA+T
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
PIN-
PACKAGE
8 µMAX
8 µMAX
GAIN
(V/V)
ADJ
100
Note:
All 8-pin µMAX packages have package code U8-1.
+Denotes a lead(Pb)-free/RoHS-compliant package.
Typical Application Circuit
5V
Applications
Automotive Transducer Applications
Strain-Gauge Amplifiers
Industrial Process Control
Battery-Powered Medical Equipment
Precision Low-Side Current Sense
Notebook Computers
Differential Voltage Amplification
R4
V
DD
/2
R3
IN-
IN+
REFIN/MODE
REF
FB
V
SS
V
DD
OUT
R2
C
FB
MAX4208
G = 1 + R2
R1
FB
R1
REF
BUFFER OUT =
V
DD
/2
µMAX is a registered trademark of Maxim Integrated Products, Inc.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Ultra-Low Offset/Drift, Precision
Instrumentation Amplifiers with REF Buffer
MAX4208/MAX4209
ABSOLUTE MAXIMUM RATINGS
V
DD
to V
SS
...............................................................-0.3V to +6V
All Other Pins ...................................(V
SS
- 0.3V) to (V
DD
+ 0.3V)
OUT Short-Circuit Duration .......................................Continuous
Current Into OUT, V
DD
, and V
SS
.......................................±25mA
Current Into Any Other Pin................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C) ............362mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DD
= 5V, V
SS
= 0V, V
CM
= V
REF
= V
DD
/2, V
REFIN/MODE
= V
SS
, R
L
= 100kΩ to V
DD
/2, V
DIFF
= (V
IN+
- V
IN-
) = 0V, MAX4208 set for
G = 100V/V (R1 = 1kΩ, R2 = 99kΩ),
T
A
= +25°C,
unless otherwise noted.) (Note 1)
PARAMETER
INPUT DC CHARACTERISTICS
Input Offset Voltage
Input Bias Current
Input Offset Current
Input Resistance
V
OS
I
B
IOS
R
IN
MAX4208, G = 100V/V
MAX4209H, G = 100V/V
-100mV
≤
V
DIFF
≤
+100mV (Note 3)
-100mV
≤
V
DIFF
≤
+100mV (Note 3)
V
CM
= V
DD
/2
Differential mode
Common mode
±3
±3
1
1
2
2
0.05
0.05
25
25
V
SS
-
0.1
106
135
±0.25
%
±0.25
150
150
V
DD
-
1.30
ppm
V
dB
±20
±20
µV
pA
pA
GΩ
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
-20mV
≤
V
DIFF
≤
+20mV
MAX4208, G = 100V/V
Gain Error
-20mV
≤
V
DIFF
≤
+20mV
MAX4209H, G = 100V/V
MAX4208, G = 100V/V
MAX4209H, G = 100V/V
V
CM
CMRR
Guaranteed by CMRR test
V
CM
= (V
SS
- 0.1V) to (V
DD
- 1.30V)
Gain Nonlinearity
(Note 2)
Input Common-Mode Range
Input Common-Mode Rejection
Ratio
2
_______________________________________________________________________________________
Ultra-Low Offset/Drift, Precision
Instrumentation Amplifiers with REF Buffer
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 5V, V
SS
= 0V, V
CM
= V
REF
= V
DD
/2, V
REFIN/MODE
= V
SS
, R
L
= 100kΩ to V
DD
/2, V
DIFF
= (V
IN+
- V
IN-
) = 0V, MAX4208 set for
G = 100V/V (R1 = 1kΩ, R2 = 99kΩ),
T
A
= +25°C,
unless otherwise noted.) (Note 1)
PARAMETER
Power-Supply Rejection Ratio
SYMBOL
PSRR
CONDITIONS
V
DD
= 2.85V to 5.5V, V
REF
= V
CM
=
(V
SS
+ 0.5V)
MIN
100
TYP
125
MAX
UNITS
dB
MAX4208/MAX4209
REFIN/MODE AND REF DC CHARACTERISTICS
REFIN/MODE Buffer Input Offset
Voltage
REFIN/MODE Input-Voltage Low
REFIN/MODE Input-Voltage High
REFIN/MODE Buffered Reference
Input Range
REFIN/MODE Buffer
Common-Mode Rejection Ratio
REFIN/MODE Buffer
Power-Supply Rejection Ratio
REFIN/MODE Bias Current
REF Common-Mode Range
REF Common-Mode Rejection
Ratio
REF, FB Bias Current
REF Input Current (MAX4209)
OUTPUT DC CHARACTERISTICS
R
L
= 100kΩ
V
OH
Output-Voltage Swing
(Notes 6 and 7)
V
OL
V
OUT
- V
SS
Source
Sink
V
DD
- V
OUT
R
L
= 10kΩ
R
L
= 1kΩ
R
L
= 100kΩ
R
L
= 10kΩ
R
L
= 1kΩ
Short-Circuit Current
Short-Circuit Recovery Time
AC CHARACTERISTICS
Gain-Bandwidth Product
Small-Signal Bandwidth
Slew Rate (Note 8)
GBW
BW
SR
MAX4208, G = 1V/V
MAX4209H, G =100V/V
MAX4208, G = 1V/V, V
OUT
= 100mV step
750
7.5
80
kHz
kHz
V/ms
I
SC
30
50
250
30
50
250
+20
-25
0.50
45
70
325
40
65
285
mA
ms
mV
I
REF
I
REFIN
V
IL
V
IH
V
REFIN/MODE
(Note 2)
Reference buffer is OFF
Shutdown mode
Reference buffer is ON, guaranteed by
REFIN/MODE CMRR test
(V
SS
+ 0.2V)
≤
V
REF/MODE
≤
(V
DD
- 1.3V)
(Note 2)
V
DD
= 2.85V to 5.5V, V
REF/MODE
= V
CM
=
(V
SS
+ 0.5V)
V
SS
< V
REFIN/MODE
< V
DD
(Note 3)
Guaranteed by reference CMRR test
(Note 4)
V
SS
≤
V
REF
≤
(V
DD
- 1.30V)
(Note 4)
MAX4208 (Note 3)
V
DIFF
= 0V (Note 5)
V
DIFF
= ±100mV (Note 5)
V
SS
106
135
1
±10
±100
V
DD
-
0.2
V
SS
+
0.2
106
100
135
125
1
V
DD
-
1.30
±10
V
SS
V
DD
V
DD
-
1.3
±40
V
SS
+
0.05
µV
V
V
V
dB
dB
pA
V
dB
pA
nA
µA
_______________________________________________________________________________________
3
Ultra-Low Offset/Drift, Precision
Instrumentation Amplifiers with REF Buffer
MAX4208/MAX4209
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 5V, V
SS
= 0V, V
CM
= V
REF
= V
DD
/2, V
REFIN/MODE
= V
SS
, R
L
= 100kΩ to V
DD
/2, V
DIFF
= (V
IN+
- V
IN-
) = 0V, MAX4208 set for
G = 100V/V (R1 = 1kΩ, R2 = 99kΩ),
T
A
= +25°C,
unless otherwise noted.) (Note 1)
PARAMETER
Settling Time
Maximum Capacitive Load
Input-Voltage Noise
Power-Up Time
Shutdown Enable/Disable Time
POWER SUPPLY
Supply Voltage
V
DD
Guaranteed by PSRR test
V
REFIN/MODE
= V
SS
,
buffer OFF
Supply Current
I
DD
(V
SS
+ 0.2V)
≤
V
REFIN/MODE
≤
(V
DD
- 1.3V), buffer ON
V
DD
= 5V
V
DD
= 5V
2.85
0.75
1.40
1.4
5.50
1.30
mA
2.30
5.0
µA
V
t
EN,
t
DIS
SYMBOL
t
S
C
L
e
n
CONDITIONS
To within 0.1% of final
value
No sustained oscillations
f = 0.1Hz to 10Hz
f = 1kHz
To within 0.1% of final value
MAX4208,
G = 1V/V
MAX4209H
MIN
TYP
10
120
200
2.5
140
20
20
pF
µV
P-P
nV/√Hz
ms
ms
MAX
UNITS
µs
V
REFIN/MODE
= V
DD
, shutdown mode
ELECTRICAL CHARACTERISTICS
(V
DD
= 5V, V
SS
= 0V, V
CM
= V
REF
= V
DD
/2, V
REFIN/MODE
= V
SS
, R
L
= 100kΩ to V
DD
/2, V
DIFF
= (V
IN+
- V
IN-
) = 0V, MAX4208 set for
G = 100V/V (R1 = 1kΩ, R2 = 99kΩ),
T
A
= -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
INPUT DC CHARACTERISTICS
MAX4208, G = 100V/V
Input Offset Voltage
V
OS
MAX4209H, G = 100V/V
MAX4208, G = 100V/V
TCV
OS
MAX4209H, G = 100V/V
(Note 3)
-100mV
≤
V
DIFF
< +100mV
MAX4208, G = 100V/V,
-20mV
≤
V
DIFF
≤
+20mV
MAX4209H, G = 100V/V,
-20mV
≤
V
DIFF
≤
+20mV
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
T
A
= +85°C
T
A
= +125°C
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
0.1
0.1
0.01
0.01
10
20
0.30
0.35
0.30
0.35
%
±45
±60
±30
±40
±0.45
±0.45
±0.17
±0.17
pA
µV/°C
µV
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Offset Voltage
Temperature Drift
(Note 2)
Input Bias Current
Gain Error
4
_______________________________________________________________________________________
Ultra-Low Offset/Drift, Precision
Instrumentation Amplifiers with REF Buffer
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 5V, V
SS
= 0V, V
CM
= V
REF
= V
DD
/2, V
REFIN/MODE
= V
SS
, R
L
= 100kΩ to V
DD
/2, V
DIFF
= (V
IN+
- V
IN-
) = 0V, MAX4208 set for
G = 100V/V (R1 = 1kΩ, R2 = 99kΩ),
T
A
= -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
-20mV
≤
V
DIFF
≤
+20mV (MAX4208),
G = 100V/V
-20mV
≤
V
DIFF
≤
+20mV (MAX4209H),
G = 100V/V
MAX4208,
G = 100V/V
G
NL
MAX4209H,
G = 100V/V
V
CM
T
A
= -40°C to
+125°C
MIN
TYP
50
MAX
180
ppm/°C
T
A
= -40°C to
+125°C
50
180
210
700
210
700
V
SS
-
0.1
96
90
96
90
dB
dB
V
DD
-
1.6
V
ppm
UNITS
MAX4208/MAX4209
Gain Error Temperature Drift
(Note 2)
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
Gain Nonlinearity
(Note 2)
Input Common-Mode Range
Input Common-Mode Rejection
Ratio
Guaranteed by CMRR test,
T
A
= -40°C to +125°C
(V
SS
- 0.1V)
≤
V
CM
≤
(V
DD
- 1.6V)
V
DD
= 2.85V to 5.5V,
V
REF
= V
CM
= V
SS
+
0.5V
T
A
= +25°C to +85°C
T
A
= -40°C to
+125°C
T
A
= +25°C to +85°C
T
A
= -40°C to
+125°C
CMRR
Power-Supply Rejection Ratio
PSRR
REFIN/MODE AND REF DC CHARACTERISTICS
REFIN/MODE Buffer Input
Offset Voltage
REFIN/MODE Buffered
Reference Input Range
REFIN/MODE Input-Voltage
Low
V
REFIN/MODE
V
IL
T
A
= +25°C to +85°C
T
A
= -40°C to +125°C
Reference buffer is ON, guaranteed by
REFIN/MODE CMRR test
Reference buffer is OFF
V
SS
+
0.2
100
100
V
DD
-
1.6
V
SS
+
0.05
µV
V
V
_______________________________________________________________________________________
5
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