MC33794 Datasheet, PDF (1/20 Pages) Motorola, Inc – Electric Field Imaging Device

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
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Electric Field Imaging Device
The 33794 is intended for applications where noncontact sensing of objects
is desired. When connected to external electrodes, an electric field is created.
The 33794 is intended for use in detecting objects in this electric field. The IC
generates a low-frequency sine wave. The frequency is adjustable by using an
external resistor and is optimized for 120 kHz. The sine wave has very low
harmonic content to reduce harmonic interference.
The 33794 also contains support circuits for a microcontroller unit (MCU) to
allow the construction of a two-chip E-field system.
Features
• Supports up to 9 Electrodes and 2 References
• Shield Driver for Driving Remote Electrodes Through Coaxial Cables
• +5.0 V Regulator to Power External Circuit
• ISO-9141 Physical Layer Interface
• Lamp Driver Output
• Watchdog and Power ON Reset Timer
• Critical Internal Nodes Scaled and Selectable for Measurement
• High-Purity Sine Wave Generator Tunable with External Resistor
Document order number: MC33794/D
Rev 6.0, 04/2003
33794
ELECTRIC FIELD
IMAGING DEVICE
DH SUFFIX
CASE 1291
44-LEAD HSOP
DWB SUFFIX
CASE 1390
54-LEAD SOICW-EP
ORDERING INFORMATION
Device
Temperature
Range (T_A)
Package
MC33794DH/R2 -40 to 85°C
44 HSOP
MC33794DWB/R2 -40 to 85°C 54 SOICW-EP
33794 Simplified Application Diagram
+12 V
47 µF
Indicator
Lamp
V_CC
10 nF
Analog_IN
Analog_IN
Analog_IN
Analog_IN
Analog_IN
MCU
ISO_Tx
ISO_Rx
Watchdog
Reset
GPx
Electrode Select
4
Shield Disable
0.1 µF ₃₃₇₉₄
V_PWR
LAMP_OUT
LP_CAP
V_CC
LEVEL
V_{DD_}MON
V_DD
PWR_MON
LAMP_MON
ISO-9141
LAMP_SENSE
ISO_IN _SIGNAL
ISO_OUT
WD_IN _{REF_A}
RST
REF_B
LAMP_CTRL
LAMP_GND
E1
TEST
E2
A, B, C, D
DIS_SHIELD _E9
SHIELD
GND
R_OSC AGND
39 kΩ
10 kΩ
47 µF
ISO-9141 Bus
Monitor (Optional)
100 pF
10 pF
1
2
Field Electrodes
9
This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Motorola, Inc. 2003