Following ADI acquisition of Linear Tech, it now appears that the LT119 dual comparator has been made obsolete. Of course, the competitor's TI LM119 represents an almost identical replacement. However, it lacks those input protection zeners much appreciated by many designers I know, especially for those applications requiring MIL or HiRel quality levels. Sure, one may add an external protection network, but the external zener capacitance does affect performances (adding series 1N4148 to reduce overall capacitance helps, but then complexity and parts count increases even further ...).
The only device currently available, and which features said input protection zeners, appears to be Renesas/Intersil ISL7119. But that is a very expensive radiation hard part. Does anybody know of any LT119 equivalent part, and thus featuring input protection zeners, which could be procured at MIL quality Level ? a cross-reference search on ADI web page did not produce any result (it hangs, searching forever ...)
Have you checked the LT319a?.It's a dual comparator and features input protection diodes.The specs are also close to that of LT119A.
Or are you also looking for the exact operating temperature and package as the LT119A for the desired replacement?LT319a operates from 0°C to 70°C and available on 14-Lead Plastic DIP package.
yes I knew about the LT319A. Indeed, it is in that very same datasheet that the LT119A is listed as obsolete, which is a pity for us that need a MIL temperature range.
but I was wondering, is by any chance so that the obsolescence of the LT119A is part of the general trend for most manufacturers to gradually dismiss MIL temperature range parts, due to the additional cost of test/characterization vs. the limited market niche ? Indeed, I know that several users of formerly MIL range parts are now forced to "uprate" commercial range equivalents. To follow the same approach for the suggested LT319A, we would need to know:
- would the LT319A mount the same die (mask, etc.) as for the LT119A, or very similar ?
- would then the different T rating basically come down to the simple fact that characterisation and testing of the parts have been cut down to a T range not as wide? and so specs may differ in their boundary values when uprating the device, though we may find them still suitable for our particular application
- would the material of the package withstand a wider T range, with no risk of cracking or breaking in some way at either -55°C and 125°C ?
I contacted the product owner for this query.I'll get back to you soon and apologies for the late response.