The DEI1049 is a BiCMOS device which contains eight differential line receivers. Each receiver channel translates incoming ARINC 429 data bus signals (tri-level RZ bipolar differential modulation) to a pair of TTL/CMOS logic outputs. Each channel operates independently and meets the requirements of the ARINC 429 Digital Information Transfer Standard.
- Octal ARINC 429 to TTL/CMOS logic line receivers
- Operates from single +5 V ± 10% or 3.3 V ± 10% power supply
- Operates in high noise environment
- Input Common Voltage Range: ± 20 V
- 2 V minimum Input hysteresis
- DEI1049 operates with external 40 kΩ resistors on inputs
- Lightning protection beyond Level 3
- Fault isolation
- Package: 38L TSSOP, 4.4 mm body
- Withstands inadvertent short to 115 Vac on inputs
Functional Description The DEI1049 is a BiCMOS device which contains eight differential line receivers. Each receiver channel translates incoming ARINC 429 data bus signals (tri-level RZ bipolar differential modulation) to a pair of TTL/CMOS logic outputs. Each channel operates independently and meets the requirements of the ARINC 429 Digital Information Transfer Standard. The device is designed to operate in a high noise environment. Inputs are accepted over a +/- 20 V common mode voltage range and the receivers provide over 2 Volts of hysteresis. Circuit speed is optimized to reject high frequency transients. The DEI1049 device provides logic level TEST inputs for built in system test. They force the outputs of all eight receivers to the specified ZERO, ONE or NULL state. The ARINC inputs are ignored when the device is in test mode. The DEI1049 has a single test port which controls all 8 channels. The DEI1049 is equivalent to the DEI1046A product, but with 40 kΩ of the input resistors removed so the part will operate with external 40 kΩ resistors. The DEI1049 ARINC inputs must be connected to the ARINC bus through 40 kΩ series resistors for correct operation. The external resistors provide fault isolation in the event of IC damage that might otherwise cause excessive loading of the ARINC signals. The ARINC inputs incorporate on-chip lightning protection by use of high value resistors on the inputs to minimize IR heating. The resistors have dielectric isolation to withstand the voltage transients. The inputs withstand lighting induced transients up to and including DO160 Level 3 pin injection levels. Higher levels can be achieved with the addition of external transient voltage suppressor (TVS) devices between the inputs and ground. The 40 kΩ resistors limit surge current and thus minimize the power requirement and size of the TVS. The ARINC inputs withstand inadvertent short to 115 Vac aircraft power without sustaining damage.