Automotive - Tyre Pressure Monitors
Swindon Silicon Systems has worked with a major automotive component company to develop a range of tyre pressure sensors that transmit pressure readings to a dashboard display. These pressure sensors utilize ASICs designed and supplied by Swindon Silicon Systems.
Tyre pressure is measured using an on-chip current source to a bridge pressure sensor. An in-car receiver picks up the RF transmission and transfers tyre pressure and tyre identity data. The unit operates on very low power giving typically 10 years of battery life.
1st Generation Tyre Pressure Monitor
Features:
- Press measurement using a frequency to voltage converter
- Pressure measurement accuracy < 2%
- Low power, typically 1uA with 32KHz Xtal oscillator and band gap
- Doubled supply for accurate pressure measurements and RF transmissions
- Programmable using EPROM
2nd Generation Tyre Pressure Monitor
Features:
- Press measurement using a dual slope auto-zeroing technique
- Pressure measurement accuracy < 0.5%
- Low power, typically 300nA with 32KHz Xtal oscillator and band gap
- Regulated doubled supply for accurate pressure measurements and RF transmissions
- Low battery measurement and transmission code
- Optional transponder interface for convenient factory or service interrogation of identity and pressure
- Temperature measurement and compensation sensor
- Selectable RF transmission protocols
- Increased programmability using fusible Zener diodes
- Temperature compensation for pressure measurement (Charles' Law)
