SN74AVC1T45: May I have some confirming item for SN74AVC1T45 application ?

Dear sir:

good day!!

One more question have any spec. mention  that regarding "SN74AVC1T45" VCCB and VCCA current consumption ?

Thanks

Dear SIR:

Good day!!

Thank for your reply.

Replay as below:

Are you connecting pin 1 to anything?==>No, The pin 1 no connect to anything. (N.C.)

Are you connecting pin 5 to anything?==>No, The pin 1 no connect to anything. (N.C.)

"The DIR pin must not be left open; its value might be read as high, or low, or oscillating. See Implications of Slow or Floating CMOS Inputs."

Also, Page 6 of the SN74AVC1T45 datasheet gives the current consumption of supply pins (written as Icca & Iccb).

==>Double confirming ,Is that mention  ICCA + ICCB  Max 20 uA  for SN74AVC1T45 total current consumption ?

Another question :

SN74AVC1T45 have any "Internal pull High or pull down " or NOT for pin 3 (A)  and Pin4(B) ?

Because SN74AVC1T45 datasheet page 16 mention "Pullup/Pulldown or Bus Hold†" on pin 3 (A)  and Pin4(B) 

(1)Is that meaning we need add "external  pull High or pull down " for  pin 3 (A)  and Pin4(B) ? (Normally application)

(2)Is that meaning we need add "external  pull High or pull down " for  pin 3 (A)  and Pin4(B) ? (below application)

    ================="external  pull High or pull down " for  pin 3 (A)  and Pin4(B)==================

SN74AVC1T45    pin 6  we have connect to 3.3V Power 

                             pin 5   NC.(No connect anything)

                             pin 2  we have connect to GND

                             pin 4  we have connect to Signal B (External pull 4.7K High 3.3V)

                             pin 1  N.C (No connect anything)

The "SN74AVC1T45" pin 3 will got "High(1.2V)" signal ?  (Because   External pull 4.7K High 1.2V))

 ======================================== 

 ================="Without external  pull High or pull down " for  pin 3 (A)  and Pin4(B)==================

SN74AVC1T45    pin 6  we have connect to 3.3V Power 

                             pin 5   NC.(No connect anything)

                             pin 2  we have connect to GND

                             pin 4  we have connect to Signal B (without External pull 4.7K High 3.3V)

                             pin 1  N.C (No connect anything)

The "SN74AVC1T45" pin 3 will got "its value might be read as high, or low, or oscillating" signal ? 

(Because pin 3 without External pull 4.7K High 1.2V) and Pin 5 (DIR) N.C (No connect anything) )

 ========================================                         

  Thanks

Hi Alex,

Can you post a screenshot of your schematic please?

Pins 1 & 6 are both supply pins, meaning this:

When converting from Voltage A --> Voltage B, Pin 1 MUST be connected to voltage A, & Pin 6 MUST be connected to voltage B.

Additionally, Pin 5 is the Direction Control pin, and it MUST be connected as follows:

If converting from A -> B : Connect Pin 5 to Voltage A.

If converting from B -> A : Connect Pin 5 to Ground.

Pin 5 CANNOT be left disconnected.

"Double confirming ,Is that mention  ICCA + ICCB  Max 20 uA  for SN74AVC1T45 total current consumption ?"

Correct, ICCA + ICCB is the maximum total current consumed from both supply pins.

To answer your other applications, I need to see a schematic.

Thanks!

Chad Crosby

Dear SIR:

Upload as attached file.

Thanks

Dear SIR:

Thanks for your reply.

But,seems didn't resolved my question,May I double confirming that :

(1)SN74AVC1T45 Pin 4 (B) and Pin3 (A) have internal pull high or low ?

     A---->B:(Because Pin 5 pull High )

       ( Change another word:

        condition 1 Pin 4 (B) and Pin3 (A) with external pull High and Pin1  no connect to P1V2 ; condition 2 without external pull high and Pin1  have connect to P1V2)

        (1-1) If Pin3 (A) didn't  provide signal ,the condition 1 Pin3 (A) will pull high by External resistor R1 ,condition 2 Pin3 (A) will pull high by Internally to Pin1(VCCA ,P1V2),Right?

        (1-2) How about  the Pin 4 (B) result in  condition 1 and  condition 2 ?

                (Is  condition 1 Pin4 (B) will pull high by External resistor R2 ,condition 2 Pin4 (B) will pull high by Internally to Pin1(VCCB ,P3V3),Right?  )

(2)condition 5 and condition 6 because Pin 5 didn't pull High or pull down," floating "

     ,therefore sometime will become A---->B  and sometime will become B------>A and sometime will become B <------>A and sometime will become B ----X----A,Right ?       

Thanks

Dear SIR:

Thank for your reply,But I more confused.Would you base on below question reply directly ?

your reply(A):

I believe condition 4 is what you're looking for.

If B ---> A, then option 4.

If A ---> B, then option 2

your reply (B):

Its hard to follow what you are asking, but I think the confusion here is whether or not the device has internal pull-ups/pull-downs. The answer is no, there are non internal. So if you leave  pins like VCC and direction pins floating then the operation will be unknown. External pull-ups will need to be used to not leave any pin floating. 

your reply(A) "option 2 and option 4 " Pin 4 (B) and Pin3 (A)  have no  External pull high and low , different your reply (B) mention that 

"External pull-ups will need to be used to not leave any pin floating."

Therefore:

(Q1)The Pin 4 (B) and Pin3 (A) external pull high /low necessary or not ?

(Q2)As your reply the Pin 4 (B) and Pin3 (A) have no internal pull high /low ,base on pin function mention "Input/output A. Referenced to VCCA"

       "Input/output B. Referenced to VCCB" ,What's the meaning regarding ""..............Referenced to VCCA"" ,".............Referenced to VCCB" ?

(Q3)

(Q3-1)For condition 1 

     Pin 4 (B) and Pin3 (A) with external pull High and Pin1  no connect to P1V2 ; condition 2 without external pull high and Pin1  have connect to P1V2)

        (Qa-1) If Pin3 (A) didn't  provide signal ,the "condition 1 and condition 3 "Pin3 (A) will pull high by External resistor R1 ,Right?

                    Because Pin1  no connect to P1V2 ,Therefore condition 1 dis-connected between Pin3 (A) and Pin4 (B) ,Right?

                    If Pin3 (A) didn't  provide signal ,the  "condition 2 and condition 4 " Pin3 (A) and Pin4 (B) will "floating",but ,connected between Pin3 (A) and Pin4 (B) ,Right?

 (Q3-2)condition 5 and condition 6 because Pin 5 didn't pull High or pull down," floating "

     ,therefore sometime will become A---->B  and sometime will become B------>A and sometime will become B <------>A and sometime will become B ----X----A,Right ?       

(Q4)

Is  it  mention regarding SN74AVC1T45   Pin1(VCCA) or  Pin6 (VCCB) either one no connect to VCCA or VCCB (Floating ) ,It will dis-connect between Pin3 (A) and Pin4 (B) ,Right ?

(Because ,Pin1(VCCA) ,  Pin6 (VCCB) are A port ,B Port internal logic supply power ,

                 Pin1(VCCA) =floating ,meaning  port A  internal logic no work ,therefore ,,It will dis-connect between Pin3 (A) and Pin4 (B)  

                 Pin6(VCCB) =floating ,meaning  port B  internal logic no work ,therefore ,,It will dis-connect between Pin3 (A) and Pin4 (B) ,too. )

(or I have any mis-understanding ?)

Thanks

Dear SIR:

Would you have any update ?

Thanks