- #1
Tom48
- 37
- 0
Hello engineers! :)I have a question bothering me i quite can't figure out.
I have a Priority encoder:
http://www.digikey.com/product-search/en?vendor=0&keywords=ls148d&stock=1
datasheet:
http://www.ti.com/lit/ds/symlink/sn74ls148.pdfAnd this RF-Switch:
http://www.digikey.com/product-detail/en/ADG904BRUZ/ADG904BRUZ-ND/1007291
datasheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/ADG904_904R.pdfNow the problem is that the RF-Multiplexer's supply voltage is 2.75V while the supply voltage of the Priority encoder is 5V.
I now would like to connect the Logic output pins (A0,A1) of the priority encoder to the logic input pins (A0,A1) of the rf-mutiplexer.
I assum that i can't just connect these 2 devices like that, thus is need to decrease the voltage somehow.I checked the datasheet of the priority encoder (page 8), it says there is a High-level output voltage of 3,3V typically (at Vcc=Min and High-level input voltage = 2V).
The first question is: If my High-level input voltage is 5V and not 2V like under test conditions, will also my High-level output voltage increase here?
Im just not sure what voltage i will get here on the output so i hope there is someone who can give me a hint here.The second question is, how do i decrease my voltage according to my needs here.
The RF-switch has a typicall data delay of 10-12ns, the priority encoder about 15ns.
So, i need a quite fast logic processing as well.I thought about a voltage divider in the first place but had to find out that this method might be just way to slow according my needs.Another possibility could be a level shifter IC, in case you would recommend this option, are there some you would use for this matter?I appreciate every little hint!
Thanks a lot in advance.Kind regards, Tom.
I have a Priority encoder:
http://www.digikey.com/product-search/en?vendor=0&keywords=ls148d&stock=1
datasheet:
http://www.ti.com/lit/ds/symlink/sn74ls148.pdfAnd this RF-Switch:
http://www.digikey.com/product-detail/en/ADG904BRUZ/ADG904BRUZ-ND/1007291
datasheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/ADG904_904R.pdfNow the problem is that the RF-Multiplexer's supply voltage is 2.75V while the supply voltage of the Priority encoder is 5V.
I now would like to connect the Logic output pins (A0,A1) of the priority encoder to the logic input pins (A0,A1) of the rf-mutiplexer.
I assum that i can't just connect these 2 devices like that, thus is need to decrease the voltage somehow.I checked the datasheet of the priority encoder (page 8), it says there is a High-level output voltage of 3,3V typically (at Vcc=Min and High-level input voltage = 2V).
The first question is: If my High-level input voltage is 5V and not 2V like under test conditions, will also my High-level output voltage increase here?
Im just not sure what voltage i will get here on the output so i hope there is someone who can give me a hint here.The second question is, how do i decrease my voltage according to my needs here.
The RF-switch has a typicall data delay of 10-12ns, the priority encoder about 15ns.
So, i need a quite fast logic processing as well.I thought about a voltage divider in the first place but had to find out that this method might be just way to slow according my needs.Another possibility could be a level shifter IC, in case you would recommend this option, are there some you would use for this matter?I appreciate every little hint!
Thanks a lot in advance.Kind regards, Tom.