DA6501.001

27 October 2008

9 (16)

APPLICATION INFORMATION

Figure 3. Resistive sensor connection circuit

Together

with

a

resistive

pressure

sensor,

MAS6501 can be used in pressure measurement

applications. Control can be performed with a micro-

controller through the I

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.

In the pressure measurement mode, the switches

marked “P” are closed and the sensor output is fed

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.

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

MCLK

SCL

SDA

Input MUX

ADC

COMMON

PI

NI

Dig.

filter

MAS9185

GND

VDD

P

P

T

T

P

T

T

Serial

Interface

Control

I

SENSOR

EOC

XCLR

MAS6501

+

GND

GND