Dear sirs,
On my desk I have some prototype cards that using the ISO1050DUB as CAN interface.
To avoid any dubt: these cards are assembled from a certified subcontractor with automatic machines, the PCB and the electric circuit are already tested, all these cards are new and never used in the field.
The ISO1050DUB is powered by a 3,3V on VCC1 and an isolated 5V on VCC2, I measured no more than 1V from GND1 and GND2 (1Mohm // 100nF are from GND1 and GND2)
The TX and RX signal are coming from a 3,3V powered CPU (the same of VCC1)
the CAN Lines are closed with a 120 ohm resistor an ESD protection is made by an NXP Tvs (pesd2can)
The ISO1050DUB has this behaviour:
measured by a scope from GND2 and CANH (or CANL it is the same): 2,5v fixed, no waweform appear when TX line is drived
measured by scope from GND1 and RX: 3,3V fixed, no waveform appear when CAN lines are drived
The IC is cold. (In a second time I measured also the IC supply current in recessive state: 1mA on VCC1 side and 7mA on VCC2 side)
I tested all my card: no one ISO1050DUB is working
In total I have checked 10 pieces of ISO1050DUB, all of this have the same lot of production; 100% have the same bad behaviour.
This is how I can read on the IC body:
First line: ISO1050
Second line: TI ZH98
Third line: 01HG4
Fortunatly I have some pieces of a different Lot (ISO1050 TI ZGP4 17HG4) This lot is working correctly!
I find on the web site http://www.ictrends.com/quality/counterfeiting-components-weekly-risks/
a one year old information about ISO1050DUBR (Lot Code ZHD7) with the same behaviour that I see .
Please reassicure me about this component, because the next month we need to start with the series production.
Thank you
Best regards
