• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 48 subscribers
  • Views 179 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

Original question:

TLV1822-Q1: Should I consider open drain maximum Low output of 250mV when setting a hysteresis?

TLV1822-Q1: Does TLV1822 Open drain output is connected to N-TYPE or P-type FET(Transsistor)?

park yongjun
Prodigy 10 points
Part Number: TLV1822-Q1
Other Parts Discussed in Thread: TLV1822

Hi team,

I am just studying TLV1822 (Open Drain output type comparator)

I have found that  if Vin+ >> Vin- , then Vout should be high. it means internal fet should be P Type FET or PNP Transistor.

So internal FET or Transistor TURNED OFF, and output is also high through the pull up resistor connected to Vpull-up

is it right? 

In my opinion, If Vin+ > Vin- , then internal output is High, and Turn on the interal N-TYPE FET, then, output is connected to Vss(GND).

Which one is correct? please give me your help.

sincerely.

  • +1
    Guru 260850 points

    A push/pull output is low when Vin+ < Vin−, or high when Von+ > Vin−.
    An open-drain output low when Vin+ < Vin−, or off when Von+ > Vin−.

    The output transistor that pulls low is an N-channel MOSFET.

  • +1
    TI__Guru 51646 points

    Hello Park,

    The output is much more complicated internally, but the "Output Control" will take care of any logic inversions. This is a very simplified diagram, mainly to show the ESD and output options.

    I put the "Logic Control" block there as, in the past, just placing a MOSFET at the output of the triangle has caused questions such as yours in the past about inversions.

    As Clemens showed, the output follows the expected comparator output response. Whichever input is greater than the other, the output will go in that direction.