MC33941_08 Datasheet, PDF (8/11 Pages) Freescale Semiconductor, Inc – Electric Field Imaging Device

BASIC CONNECTIONS
PIN DESCRIPTIONS
DGND
N/C
SHIELDEN
C
B
A
LEVEL
LPCAP
ROSC
VDDCAP
VPWR
VCCCAP
N/C
E7
E6
E5
E4
E3
E2
E1
TEST
GND
SHIELD
AGND
Figure 5. Pin Descriptions
Table 5. Electrode Selection
Terminal/SIGNAL
C
No electrodes selected
0
E1
0
E2
0
E3
0
E4
1
E5
1
E6
1
E7
1
B
A
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
Table 6. Pin Description
Pin
Number
Pin Name
Definition
1
2, 24
3
4,5,6
7
DGND
N/C
SHIELDEN
C, B, A
LEVEL
Connected to the ground return
These pins should be left open.
Used to enable the shield signal
Controls electrode or reference activity
This is the detected, amplified, and
offset representation of the signal
voltage on the selected electrode
8
LPCAP ^{A capacitor on this pin forms a low pass}
filter with the internal series resistance
from the detector to this pin
9
ROSC A resistor from this pin to circuit ground
determines the operating frequency of
the oscillator
10
VDDCAP ^{A 47μF capacitor is connected to this}
pin to filter the internal analog regulated
supply
11
VPWR ^{12 V power applied to this pin will be}
converted to the internal regulated
voltages needed to operate the part
12
VCCCAP ^{A 47μF capacitor is connected to this}
pin and VCCCAP provides a regulated
5.0 V to power external circuits 75 mA
Max
13
AGND ^{Connected to the ground return of the}
analog circuitry
14
SHIELD ^{Connects to cable shields to cancel}
cable capacitance.
15
16
17-23
GND
TEST
E1 – E7
Main IC ground
Connect to circuit ground
Electrode pins
MCU
Power
Analog In
Electrode Select
Shield Enable
+5V
47uF
47uF
MC33941
VCCCAP
ROSC
VDDCAP
LPCAP
LEVEL
3
A, B, C
SHIELDEN
+12V
VPWR
TEST
AGND
GND
E1
E7
SHIELD
39k
10nF
Field Electrodes
(E1 through E7)
MC33941
8
Figure 6 . Simplified Application Diagram
Sensors
Freescale Semiconductor