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2009-05-17 by michael tenore
I was rechecking the design of of a board that I will be making in the next few days and I just noticed the pinout of the Texas Instrument 74LS157 is different than the pinout from Fairchild or Signetics? TI says Inputs 3A=11 3B=10 4A=14 4B=13! Everyone else has it as 3a=14 3b=13 4a=11 4b=10! who is right? Even the Library in ExpressSCH has it other than what TI shows in thier Data BooksTI? I dont know which one to trust! Regards Mike
2009-05-17 by michael tenore
Never mind my last post! I see what they did. They are mixing apples and oranges.. I have to stop reviewing my designs at 3am! Sorry Guys mike ________________________________
From: michael tenore <wb2lcw@...> To: Homebrew_PCBs@yahoogroups.com Sent: Saturday, May 16, 2009 8:35:40 PM Subject: [Homebrew_PCBs] 74LS157 pinouts? I was rechecking the design of of a board that I will be making in the next few days and I just noticed the pinout of the Texas Instrument 74LS157 is different than the pinout from Fairchild or Signetics? TI says Inputs 3A=11 3B=10 4A=14 4B=13! Everyone else has it as 3a=14 3b=13 4a=11 4b=10! who is right? Even the Library in ExpressSCH has it other than what TI shows in thier Data BooksTI? I dont know which one to trust! Regards Mike [Non-text portions of this message have been removed]
2009-05-17 by Donald H Locker
Hi, Michael. As long as 3out and 4out move with the 3a/b and 4a/b designation, there should be no difficulty. In other words, it doesn't matter whether the gate is called 3 or 4; if the corresponding output still corresponds, not problems. HTH, Donald.
----- Original Message ----- From: "michael tenore" <wb2lcw@...> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com> Sent: Saturday, May 16, 2009 8:35:40 PM GMT -05:00 US/Canada Eastern Subject: [Homebrew_PCBs] 74LS157 pinouts? I was rechecking the design of of a board that I will be making in the next few days and I just noticed the pinout of the Texas Instrument 74LS157 is different than the pinout from Fairchild or Signetics? TI says Inputs 3A=11 3B=10 4A=14 4B=13! Everyone else has it as 3a=14 3b=13 4a=11 4b=10! who is right? Even the Library in ExpressSCH has it other than what TI shows in thier Data BooksTI? I dont know which one to trust! Regards Mike