Tire Pressure Generation TIS-10 Wheel Unit Type ASK/FSK 315 MHz 1 of 3 1. SYSTEM OVERVIEW The tire pressure monitoring system (referred as TG for Tire Guard) consists of the following units:
- Tire guard wheel unit type TIS-10 which includes an integrated pressure, temperature and acceleration sensor and a RF transmitter.
- LF receiver unit which includes a LF receiver (not described in this document) The TG monitors a vehicle's tire pressure whilst driving or stationary. An electronic unit (wheel unit) inside each tire, mounted to the valve stem, periodically measures the actual tire pressure. By means of RF communication, this pressure information is transmitted to the RF receiver. 2. TECHNICAL DESCRIPTION Carrier frequency:
Number of channels:
Type of modulation:
Baud rate:
Rated Output Power:
Antenna:
Voltage supply range:
315 MHz 1 Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK) 9600bps
< 10mW Internal 2.1 up to 3.2V 3. TYPICAL USAGE PATTERN 3.1 AVERAGE FACTOR CALCULATION (Standard 47 CFR Part 15C (periodic intentional transmitter)) Maximum transmitting duration in whatever 100ms windows: 10.31ms
Averaging factor = 20xlog(10.31/100)=-19.73dB Baudrate Framebyte Framebits Framebits tbit
:=
+
:=
9600bps
:=
12byte
:=
Framebyte 98=
ToleranceBaudrate 1%:=
2bit 1 Baudrate 1 ToleranceBaudrate
(
)
=
0.10522ms tbit tFramebits tFramebits tFrameFSKbits
:=
=
tbit Framebits 10.31145ms
:=
tFramebits 1 due to FSK 100%
AveragingFactor_tFrame
:=
20log
tFrameFSKbits 100ms
Averaging Factor_tFrame = -19.8dB 2 of 3 ASK WUP: 320 bits Baudrate= 9600bps/s (+/-1%) ASK: 50% duty cycle Max WUP duration = 16.83ms AveragingFactor_tWUP
:=
20log
tWUPFrameASKbit 100ms
Averaging Factor_tWUP = -15.5dB 4. BLOCK DIAGRAM The block diagram below shows the main electronic units of the wheel unit:
Note: The time between inter frames is always higher than the 100ms FCC window. This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. 26M H z Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Le prsent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorise aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radiolectrique subi, mme si le brouillage est susceptible d'en compromettre le fonctionnement. tem perature, acceleration sensor and controller RF C IR CU IT Learning coil ANT EN NA Pressure, 3V X tal LITH IUM BA TTE RY RF Chipset: Infineon SP001650684 26MHz Xtal (Quartz): NDK2016A or KSS CX2016DB 3 of 3