APGRD003 Microchip Technology, APGRD003 Datasheet - Page 21

• Manufacturer Part Number: APGRD003
• Description: KIT TPMS REFERENCE DESIGN
• Manufacturer: Microchip Technology
• Type: Automotive, Tire Pressure Monitorr

Specifications of APGRD003

• Frequency: 433.92MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC18F4680, PIC18F2680, MCP2030
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

© 2006 Microchip Technology Inc.
3.4.3.1
When a Learn Mode ID is received, the module will save the new Tire Location ID and
use it as its default ID for all future normal transmissions until another Learn Mode ID
is received. This feature can be used to "re-learn" the tires after tire rotations or if a new
Transponder Sensor module has been installed.
3.4.3.2
The user configurable output filter of the MCP2030 is utilized to prevent the
microcontroller from being awakened unnecessarily by either noise or LF signals from
other unknown sources. The data is outputted to the microcontroller only when the pre-
amble of the incoming message matches the pre-configured filter settings. The
MCP2030 can be configured via SPI by writing to the seven configuration registers
through the microcontroller. The number of channels enabled can also be controlled
through these configuration registers. Refer to the MCP2030 data sheet (DS21981) for
more information.
3.4.3.3
The incoming LF message from the LF Initiator Module consists of the following in a
125 kHz modulated format:
• A required minimum of 4 ms ON time for AGC stabilization
• A 500 μs OFF delay
• A 2 ms ON time for the output filter (user configurable in AFE)
• A 2 ms OFF for the output filter time (user configurable in AFE)
• Two bytes of data (maximum of 8 bytes)
FIGURE 3-3:
- Tire Location ID (user defined)
- System Mode ID (user defined)
Note:
125 kHz Base Frequency
Mode ID (1 byte)
LEARN MODE OVERVIEW
ANALOG FRONT END OVERVIEW
LF MESSAGE OVERVIEW
Due to the possibility that one LF Initiator can wake up multiple Transpon-
der Sensor modules in a full system setup (4 LF Initiators with 4 Sensor
Modules) during development due to the close proximity, either the
transmitting power of the LF Initiators should be reduced or the distance
between the module sets (1 set = 1 LF Initiator + 1 Transponder Sensor)
should be kept at a maximum where they will not cause interference with
each other. Refer to Application Note AN232 for more details on the LF
Transmitter.
Data
Tire Location ID
LF MESSAGE FORMAT
(1 byte
2 ms
Transmission Direction LSb First
Wake-Up 125 kHz Preamble
2 ms
4 ms
LOGIC ‘0’
LOGIC ‘1’
DS51624B-page 17
Period
Bit