MLX90308CCC Datasheet, PDF (24/26 Pages) Micro Electronics – Programmable Sensor Interface

Figure 10. Application Example
MLX90308CCC
Programmable Sensor Interface
Figure 10a. Programmable Oil Pressure Gauge
Communications
Signal Out
GND
V+
Programmable Oil Pressure Gauge
This application example illustrates a fundamental
application of the MLX90308 and a bridge type
pressure sensor element. In this application, the
MLX90308 uses an external FET as a pass transistor to
regulate the voltage to the sensor and the analog portion
of the IC. This is known as Absolute Voltage Mode, where
voltage to the sensor and analog circuit is regulated independent
of the supply voltage. The MLX90308 can be operated in Ratiometric
Voltage Mode, in which the output (VMO) is tied to an A/D converter
sharing the same supply and ground reference. A third wiring option is
Current Mode, which allows the user a 4 to 20 milliampere current range to use as a
2-wire analog sensor.
Figure 10b. Programmable Oil Pressure Gauge Electrical Connections
Pressure
Sensor
1
IO1
2
IO2
3
TSTB
4
FLT
5
OFC
6
VBN
7
VBP
8
TMP
COMS
GND
CMN
CMO
VMO
VDD1
FET
VDD
Communication
16
s
GND
15
14
13
12
11
G
10
External FET
for Regulation
9
Oil
Pressure
(psi)
Signal Out
V
+
D
S
MLX90308CCC Programmable Sensor Interface Page 24
Rev 2.2
23/Oct/01