Datasheet

www.maximintegrated.com
Maxim Integrated │ 24
MAX11200/MAX11210 24-Bit, Single-Channel, Ultra-Low-Power,
Delta-Sigma ADCs with GPIO
Figure 8. RTD Temperature Measurement Circuit
Applications Information
See Figure 8 for the RTD temperature measurement
circuit and Figure 9 for a resistive bridge measurement
circuit.
Magnetic force restoration (MFR) force-measuring (typi-
cally weight) systems are a good design example requir-
ing an ADC that has exceptional dynamic range and lin-
earity. MFR devices use a lever and fulcrum to balance
an unknown weight (the object to be measured) with
an electromagnetic force coil. The current necessary to
keep the balance in equilibrium is equal to the force of
gravity exerted to the object to be weighed.
These currents can be as large as several hundred
amperes, or as small as several microamperes, all in the
same system. Often, it is necessary to maintain the given
accuracy across the entire scale.
This application requires a quantizing device with
enough resolution and dynamic range to match the sen-
sor system. In the past, this was done using an audio
ADC and DAC under the control of a microprocessor to
build a discrete delta-modulator-style A/D. This was very
expensive, and could decrease the mean time between
failure (MTBF) for measurement devices requiring high
reliability. The MAX11200/MAX11210 ADCs offer a much
simpler solution with excellent resolution and dynamic
range. See Figure 10.
Chip Information
PROCESS: BiCMOS
Figure 9. Resistive Bridge Measurement Circuit
I
REF2
I
REF1
I
REF1
= K x I
REF2
REFP
REFN
R
REF
AINP
AINN
GND
R
RTD
MAX11200
MAX11210
REFP
AVDD
REFN
AINP
AINN
MAX11200
MAX11210