Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
Output Overload Recovery
Pin Configurations
Autozeroing amplifiers typically require a substantial
amount of time to recover from an output overload. This
TOP VIEW
is due to the time it takes for the null amplifier to correct
MAX4238/
MAX4238/
MAX4239
the main amplifier to a valid output. The MAX4238/
MAX4239 require only 3.3ms to recover from an output
overload (see Electrical Characteristics and Typical
Operating Characteristics).
MAX4239
SHDN
IN-
1
2
3
4
8
7
6
5
N.C.
OUT
GND
IN+
1
2
3
6
5
4
V
CC
V
CC
Shutdown
The MAX4238/MAX4239 feature a low-power (0.1µA)
shutdown mode. When SHDN is pulled low, the clock
stops and the device output enters a high-impedance
SHDN
IN-
IN+
OUT
N.C.
GND
state. Connect SHDN to V
for normal operation.
CC
SO
SOT23
Applications Information
Chip Information
Minimum and Maximum Gain
Configurations
TRANSISTOR COUNT: 821
PROCESS: BiCMOS
The MAX4238 is a unity-gain stable amplifier with a gain-
bandwidth product (GBWP) of 1MHz. The MAX4239 is
decompensated for a GBWP of 6.5MHz and is stable with
a gain of 10V/V. Unlike conventional operational ampli-
fiers, the MAX4238/MAX4239 have a maximum gain
specification. To maintain stability, set the gain of the
MAX4238 between A = 1000V/V to 1V/V, and set the
V
gain of the MAX4239 between A = 6700V/V and 10V/V.
V
ADC Buffer Amplifier
The low offset, fast settling time, and 1/f noise cancella-
tion of the MAX4238/MAX4239 make these devices
ideal for ADC buffers. The MAX4238/MAX4239 are well
suited for low-speed, high-accuracy applications such
as strain gauges (see Typical Application Circuit).
Error Budget Example
When using the MAX4238/MAX4239 as an ADC buffer,
the temperature drift should be taken into account when
determining the maximum input signal. With a typical off-
set drift of 10nV/°C, the drift over a 10°C range is 100nV.
Setting this equal to 1/2LSB in a 16-bit system yields a
full-scale range of 13mV. With a single 2.7V supply, an
acceptable closed-loop gain is A = 200. This provides
V
sufficient gain while maintaining headroom.
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