U6268B Datasheet, PDF (1/14 Pages) TEMIC Semiconductors – Side-Airbag Sensor Dual Interface

Features
• Two Identical Interface Channels
• Pre-regulated Smoothed Voltage and a Supply Current up to 50 mA for the Sensors
• Data from the Sensors by Current Modulation with a Transmission Rate of 60 kBaud
(Transmission Bandwidth 500 kHz)
• TTL-compatible Input Activates the Sensor
• Data Output Can be Directly Connected to a Microcontroller Input
• Operation Supply Voltage Range 5.7V ≤ V_S ≤ 40V
• ESD Protection According to MIL-STD-883C Test Method 3015.7
• High-level EMI Protection
Benefits
• Simple Wiring Thanks to One Common Line for Supply of the Sensor and Data
Transmission from the Sensor to the U6268B
• Current Modulation Provides High Noise Immunity for Data Transfer
Side-airbag
Sensor Dual
Interface
U6268B
1. Description
The U6268B is an interface IC for remote automotive sensors. It links the crash sen-
sors in the driver and passenger door with the main airbag unit in the dashboard. Two
identical channels supply the external sensors and receive digital information from
them via one active wire each. The interface supplies the external sensors with a pre-
regulated smoothed voltage, the external units transmit the digital information back to
the interface by current modulation.
As the device is designed for safety-critical applications, the highest data transmission
security is mandatory. With high immunity against cross coupling between the two
channels, the U6268B is tailored for the harsh automotive environment.
Figure 1-1. Block Diagram
Data
Channel 1
Enable
Voltage
comparator
Channel 1
Channel 2
Enable
Channel 2
Data
Voltage
comparator
I/V converter
Smoothed voltage
regulator
Temperature Short circuit
monitor
detection
Smoothed voltage
regulator
I/V converter
Channel 1
power
supply
Data
trans-
mission
Crash
sensor
Channel 2
power
supply
Data
trans-
mission
Crash
sensor
Rev. 4808B–AUTO–09/05