• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 48 subscribers
  • Views 1664 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM311: Suggest me a better/faster option for a comparator

Slavisa Micic
Prodigy 20 points
Part Number: LM311
Other Parts Discussed in Thread: TLV3201

HI,

I have developed my circuit design where I adopt LM311 as a main comparator. Response time is about 200ns and I consider this as not so fast or not acceptable. Can you suggest me a comparator IC which is quite faster than this? Power supply is (0, +15VDC) and input signal is (0, +10Vmax). Everything is ground referenced.

  • 0
    TI__Mastermind 25970 points

    Slavisa

    Unfortunately we do not have a comparator that can operate at 15V which is faster than the LM311.

    If you wish to share more details about your application, maybe we can find a solution around the high operating voltage requirement.

    Chuck

  • 0 in reply to Chuck Sins
    Prodigy 20 points

    Thank you.

    In the meantime, I changed some details regarding power supply levels. LM311 is now at 5VDC, input levels are 0-5VDC, output 5-0VDC (inverting opamp). Offset is set in range 1-4.16VDC. Reaction time is somewhat lower. I would like to see some faster circuitry, just to compare... 

  • 0 in reply to Slavisa Micic
    TI__Mastermind 25970 points

    Our TLV3201 family is a 5V, 40ns prop delay device.  This device also has a push-pull output stage which should be better for you if the output needs to toggle frequently and level-shifting is not required.

    Chuck

  • 0
    Prodigy 10 points

    You may want to take a look at the AD790.  It handles ±15V supplies and inputs.  Prop delay strictly less than 45ns, approaching 20ns for large input over-drives.  

    I agree that reducing the operating voltage is preferable, assuming it doesn't mess up some other aspect of your timing.  Once you need a fast comparator to operate outside of ±5V, your options become very limited.  

  • 0 in reply to Andrew Hutchison
    TI__Mastermind 25970 points

    Slavisa

    Andrew's comments are fair.  There are limited choices at higher operating voltages.  Frequently such devices are used to protect against high amplitude transients and then level shift on the output to a lower voltage level.   Hopefully the information you have received will allow you to move forward.

    Chuck