Automotive TPMS Solution

TPMS battery life depends on transmission frequency, sleep current, and battery capacity. Typical configuration with MSP-100KPA-A: 1) Sleep current <5uA (sensor + microcontroller)

2) Transmission current 5-10mA for 10ms every 60 seconds

3) CR2032 battery (225mAh capacity). Calculated battery life: Average current = 5uA + (10mA × 0.0167s/60s) = 7.8uA. Battery life = 225mAh / 7.8uA = 28,800 hours = 3.3 years. Optimizing to 5uA average with lower transmission frequency can achieve 5+ years. Actual life depends on duty cycle, temperature, and battery quality.

Design for <5uA sleep current and optimize transmission frequency for your application requirements. Use high-quality batteries for maximum life.

TPMS EMC compliance requires attention to both emissions and immunity: 1) Conducted emissions - implement proper power supply filtering with ferrite beads and capacitors

2) Radiated emissions - follow RF layout best practices with proper antenna design and ground planes

3) Radiated immunity - use shielding and filtering to protect sensitive analog circuits

4) ESD protection - add TVS diodes on external connections

5) Transient immunity - protect against load dump and other automotive transients. The MSP-100KPA-A has good EMC performance when properly integrated. Pre-compliance testing is recommended before formal certification testing.

Follow automotive EMC design guidelines and conduct pre-compliance testing early. Contact our FAE for EMC troubleshooting support.

While the MSP-100KPA-A is designed for direct TPMS (measuring actual tire pressure), it can also be used in indirect TPMS systems that estimate tire pressure through wheel speed analysis. However, indirect TPMS typically doesn't require pressure sensors in the wheel - it uses existing ABS wheel speed sensors. For hybrid systems that combine direct and indirect monitoring, the MSP-100KPA-A provides the direct pressure measurement component. The sensor's fast response and accuracy make it suitable for both direct TPMS and as a reference for indirect system calibration.

For indirect TPMS, you typically don't need pressure sensors. Use MSP-100KPA-A for direct TPMS or hybrid systems requiring actual pressure measurement.

TPMS production calibration typically includes: 1) Pressure calibration - apply known pressures (0, 50, 100kPa) and record sensor output

2) Temperature calibration - test at multiple temperature points if required

3) RF calibration - verify transmission power and frequency

4) ID programming - assign unique sensor ID. The MSP-100KPA-A is factory-calibrated, but system-level calibration may be needed for highest accuracy. Most customers implement a two-point pressure calibration (zero and span) at production. Calibration equipment includes pressure standards, temperature chambers, and RF test equipment. BeiLuo provides calibration guidelines and can recommend equipment suppliers.

Implement at least two-point pressure calibration in production. Contact our FAE for detailed calibration procedures and equipment recommendations.

TPMS sensor replacement and pairing procedures: 1) Each sensor has a unique ID programmed during production

2) Vehicle ECU learns sensor IDs through a learn/pairing procedure

3) Common methods include: OBD-II tool activation, magnet activation, or automatic learning during drive

4) When replacing sensors, the new sensor IDs must be learned by the ECU

5) Some systems require all four sensors to be replaced/learned simultaneously. BeiLuo provides sensor IDs in barcode format for easy scanning during installation. Our FAE team can provide guidance on implementing learn procedures for specific vehicle platforms.

Implement a sensor learning procedure compatible with your vehicle platform. Contact our FAE for ID format and learning procedure recommendations.

Valve-stem and strap-mounted TPMS sensors have different design considerations: 1) Valve-stem mounting - sensor attached to valve stem, compact design, requires valve replacement, direct air pressure access

2) Strap/band mounting - sensor strapped to wheel rim, larger package, no valve modification, may require air tube connection. The MSP-100KPA-A in SOP-8 package is suitable for valve-stem mounting due to its compact size. Strap-mounted designs often use larger packages with more features. Valve-stem mounting is more common in passenger vehicles due to compact size and easy installation. Strap mounting is used in some commercial vehicles and retrofit applications.

Choose valve-stem mounting for compact OEM designs. Consider strap mounting for retrofit or special applications. The MSP-100KPA-A suits valve-stem designs.