APGRD003 Microchip Technology, APGRD003 Datasheet - Page 19

• 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.
3.4.2.6
The module is powered by a standard Lithium 3V coin cell battery.
To reduce power consumption, the LED used for indication should be removed to
reduce the standby current consumption. The typical standby current without the LED
is about 25 μA (the sum of the power down current of the microcontroller and the active
current of three-channel analog front end).
In addition, the LF Receiver has all three channels enabled and powered on all the time
for incoming signal detection. One or two channels can be disabled or a periodic
detection method can be implemented to further reduce the overall standby current
usage. Refer to Appendix A. “Schematic and Layouts”.
3.4.3
When the Transponder Sensor module receives a LF (125 kHz) wake up challenge
message, the Analog Front End validates the incoming challenge. Only after a valid
message has been received, the microcontroller is awakened from sleep mode. The
action taken by the module is determined by the received commands. Normal request
measures the tire pressure and temperature. Learn Mode request assigns a new ID to
the sensor module for future operations prior to the measurements. The Transponder
Sensor module then transmits the data to the base station via UHF (433.9 MHz) and
returns to Sleep mode if no other interrupts were detected.
To reduce power consumption, the pressure sensor and the op-amp for signal
amplifications are normally powered off. These two devices are powered on only during
measurements.
POWER
Operation Overview
DS51624B-page 15