DA6501.001
27 October 2008
APPLICATION INFORMATION
+
CVDD
VDD
GND
R1
Input MUX
P
MCLK
PI
NI
SENSOR
Control
P
EOC
Dig.
filter
T
T
ADC
SDA
I2
C
Serial
Interface
SCL
XCLR
R4
R3
R2
MAS9185
MAS6501
T
P
T
COMMON
GND
GND
Figure 3. Resistive sensor connection circuit
Together with resistive pressure sensor,
MAS6501 can be used in pressure measurement
applications. Control can be performed with a micro-
controller through the I2C serial interface.
a
through to the ADC. In the temperature
measurement mode, the switches marked “T” are
closed and the voltage at the ADC input is
determined by the internal resistor array and the
temperature-dependent resistance of the sensor. In
this configuration the sensor bridge is connected as
part of single four resistor bridge circuit where other
four resistors (R1, R2, R3, R4) are inside the IC.
The sensor is connected between the power supply
voltage (VDD) and MAS6501 signal ground
(COMMON) which can be internally (switch inside of
MAS6501) connected to ground (GND). Sensor
output is read as a differential signal through PI
(positive input) and NI (negative input) to the ∆Σ
converter in MAS6501.
To guarantee conversion accuracy a supply voltage
decoupling capacitor of 4.7 µF or more should be
placed between VDD and GND of MAS6501 (see
In the pressure measurement mode, the switches
marked “P” are closed and the sensor output is fed
C
VDD in figure 3).
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MAS [ MICRO ANALOG SYSTEMS ]
