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LP211: Bipolar Window Comparator > LP211 good choice or more recent option?

Part Number: LP211
Other Parts Discussed in Thread: TLV1702, LP311, LM311, LM6511

Dear Team,

our customer looks for a window comparator for:

  • VIH=5V, VIL=-5V.
  • For Vin>VIH or Vin<VIL, output "1".
  • For VIL<Vin<VIH, output "0".

I saw that we have a TINA TI example, based on the LP211, that is demonstrating a similar implementation - see below.

The LP211 is an older device, so I wanted to look for a more recent option. However, I could not find any comparator with full pin-out of collector and emitter. I played around with the TLV1702 in TINA TI - since the output transistor has a emitter that is tied to V-, the output signal would not be 0...5V in a similar schematics of the screenshot from below. 

> Do we have some newer LP211 or another ref design for this functionality?

Thanks and best regards

  • Hello Martin,

    The LP311/LM311 family was specifically designed for bipolar supplies and inputs while interfacing to ground-referenced logic-level inputs. The output stage was specifically designed to be able to ground-reference using either a pull-up to positive, or pull-down to negative logic.

    The window comparator circuit is common and could be used with any comparator, but most of the "newer" comparators are designed for single supplies and the output would swing to the comaprators negative pin, requiring external level-shifting circuitry to interface to ground referenced logic levels (usually just creating a voltage divider with the pull-up resistor so that "low" is near GND).

    There is a "newer' version, the LM6511, which extends the minimum supply voltage down to 2.7V.

    There is also the dual version, the the LM319 (minus the offset nulling and strobe inputs). This would be ideal for the window comaprator.

    But, no, we do not have any "newer" devices that use the unique ground-referenced output as used on the LM311/ LM319 family. Even though they are "old", they are still popular and are not in any danger of disappearing.

  • Hello Paul,

    Thanks a lot for the answer and the details. Yes, I think that a LM311/LM319 could be sufficient in this case - let see if the package options are fine.

    I will review the options.

    Best Regards