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Looking for SMD level shifters to TTL

Started by John Robertson September 4, 2021
Working on a FPGA project and we need perhaps 30 level shifter gates.

Anyone work with 3.6 to 5.0 volt interfaces that can recommend any 
single part over the rest before I spend a few hours digging through 
Digi/Mouser/Newark's inventory?

In some cases we can get away with resistors, but there is a bit of TTL 
level drivers needed.

Thanks!

John :-#)#
-- 
(Please post followups or tech inquiries to the USENET newsgroup)
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søndag den 5. september 2021 kl. 01.33.28 UTC+2 skrev John Robertson:
> Working on a FPGA project and we need perhaps 30 level shifter gates. > > Anyone work with 3.6 to 5.0 volt interfaces that can recommend any > single part over the rest before I spend a few hours digging through > Digi/Mouser/Newark's inventory? > > In some cases we can get away with resistors, but there is a bit of TTL > level drivers needed. >
Vih for TTL is 2.0V that is well within the Voh of 3.3V CMOS
On 2021/09/04 4:47 p.m., Lasse Langwadt Christensen wrote:
> søndag den 5. september 2021 kl. 01.33.28 UTC+2 skrev John Robertson: >> Working on a FPGA project and we need perhaps 30 level shifter gates. >> >> Anyone work with 3.6 to 5.0 volt interfaces that can recommend any >> single part over the rest before I spend a few hours digging through >> Digi/Mouser/Newark's inventory? >> >> In some cases we can get away with resistors, but there is a bit of TTL >> level drivers needed. >> > > Vih for TTL is 2.0V that is well within the Voh of 3.3V CMOS > >
My designer is looking to use something like the MAX3001e, I don't think it plays well with TTL. I did spot TI's CB3T on a message board on Xilinx: https://forums.xilinx.com/t5/Other-FPGA-Architecture/How-to-select-an-appropriate-level-shifter-KC705-eval-brd/td-p/741714 Just looking for a few ideas here of chips/workarounds to consider. Thanks! John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."
søndag den 5. september 2021 kl. 01.54.57 UTC+2 skrev John Robertson:
> On 2021/09/04 4:47 p.m., Lasse Langwadt Christensen wrote: > > søndag den 5. september 2021 kl. 01.33.28 UTC+2 skrev John Robertson: > >> Working on a FPGA project and we need perhaps 30 level shifter gates. > >> > >> Anyone work with 3.6 to 5.0 volt interfaces that can recommend any > >> single part over the rest before I spend a few hours digging through > >> Digi/Mouser/Newark's inventory? > >> > >> In some cases we can get away with resistors, but there is a bit of TTL > >> level drivers needed. > >> > > > > Vih for TTL is 2.0V that is well within the Voh of 3.3V CMOS > > > > > My designer is looking to use something like the MAX3001e, I don't think > it plays well with TTL. I did spot TI's CB3T on a message board on Xilinx: > > https://forums.xilinx.com/t5/Other-FPGA-Architecture/How-to-select-an-appropriate-level-shifter-KC705-eval-brd/td-p/741714 > > Just looking for a few ideas here of chips/workarounds to consider. > Thanks! >
is the FPGA output or input?
On Sat, 4 Sep 2021 16:33:16 -0700, John Robertson <spam@flippers.com>
wrote:

>Working on a FPGA project and we need perhaps 30 level shifter gates. > >Anyone work with 3.6 to 5.0 volt interfaces that can recommend any >single part over the rest before I spend a few hours digging through >Digi/Mouser/Newark's inventory? > >In some cases we can get away with resistors, but there is a bit of TTL >level drivers needed. > >Thanks! > >John :-#)#
What levels? -- Father Brown's figure remained quite dark and still; but in that instant he had lost his head. His head was always most valuable when he had lost it.
On Saturday, September 4, 2021 at 7:33:28 PM UTC-4, John Robertson wrote:
> Working on a FPGA project and we need perhaps 30 level shifter gates. > > Anyone work with 3.6 to 5.0 volt interfaces that can recommend any > single part over the rest before I spend a few hours digging through > Digi/Mouser/Newark's inventory? > > In some cases we can get away with resistors, but there is a bit of TTL > level drivers needed.
So you need both drivers and receivers? If it is TTL drivers, CMOS 3.3V is compatible with that I thought, no? For the receivers I like to use quickswitch type devices. A current design uses 10 wide '240 type devices, SN74CBTD3384CPW. They still seem to be available in spite of the shortage... at the moment. TI has 16,000 in stock. They act to limit the voltage passing through the switch to around 3.3V give or take, I don't recall the details. The prop delay through the switch is lightning fast. Only the enable runs through logic with noticeable delays. -- Rick C. - Get 1,000 miles of free Supercharging - Tesla referral code - https://ts.la/richard11209
On 9/4/2021 7:33 PM, John Robertson wrote:
> Working on a FPGA project and we need perhaps 30 level shifter gates. > > Anyone work with 3.6 to 5.0 volt interfaces that can recommend any > single part over the rest before I spend a few hours digging through > Digi/Mouser/Newark's inventory? > > In some cases we can get away with resistors, but there is a bit of TTL > level drivers needed. > > Thanks! > > John :-#)#
Sounding like a broken record proselytizing these things but a number of the Greenpak SPLCs have dual rails so you can have level-shifted IO of arbitrary configuration, they're pretty cheap in quantity, and the mfgr will program them for you. <https://www.dialog-semiconductor.com/products/greenpak> And you can put some logic in 'em, too!
On Saturday, September 4, 2021 at 9:13:13 PM UTC-4, bitrex wrote:
> On 9/4/2021 7:33 PM, John Robertson wrote: > > Working on a FPGA project and we need perhaps 30 level shifter gates. > > > > Anyone work with 3.6 to 5.0 volt interfaces that can recommend any > > single part over the rest before I spend a few hours digging through > > Digi/Mouser/Newark's inventory? > > > > In some cases we can get away with resistors, but there is a bit of TTL > > level drivers needed. > > > > Thanks! > > > > John :-#)# > Sounding like a broken record proselytizing these things but a number of > the Greenpak SPLCs have dual rails so you can have level-shifted IO of > arbitrary configuration, they're pretty cheap in quantity, and the mfgr > will program them for you. > > <https://www.dialog-semiconductor.com/products/greenpak> > > And you can put some logic in 'em, too!
I'm glad you do keep mentioning them. I believe they are pretty cheap in quantity, no? You develop your program and they supply them for production already programmed, no? Can they compete with a 10 bit shifter that costs a quarter? What's the propagation delay pin to pin as buffers? -- Rick C. + Get 1,000 miles of free Supercharging + Tesla referral code - https://ts.la/richard11209
On 9/4/2021 10:26 PM, Rick C wrote:
> On Saturday, September 4, 2021 at 9:13:13 PM UTC-4, bitrex wrote: >> On 9/4/2021 7:33 PM, John Robertson wrote: >>> Working on a FPGA project and we need perhaps 30 level shifter gates. >>> >>> Anyone work with 3.6 to 5.0 volt interfaces that can recommend any >>> single part over the rest before I spend a few hours digging through >>> Digi/Mouser/Newark's inventory? >>> >>> In some cases we can get away with resistors, but there is a bit of TTL >>> level drivers needed. >>> >>> Thanks! >>> >>> John :-#)# >> Sounding like a broken record proselytizing these things but a number of >> the Greenpak SPLCs have dual rails so you can have level-shifted IO of >> arbitrary configuration, they're pretty cheap in quantity, and the mfgr >> will program them for you. >> >> <https://www.dialog-semiconductor.com/products/greenpak> >> >> And you can put some logic in 'em, too! > > I'm glad you do keep mentioning them. I believe they are pretty cheap in quantity, no? You develop your program and they supply them for production already programmed, no? Can they compete with a 10 bit shifter that costs a quarter? What's the propagation delay pin to pin as buffers? >
I think the cheapest device with the capability to 10 bit de-serialize (if that's what you mean would be the SLG47503, 30 cents programmed in quantities of 500, 25 cents in quantities of 3000+. I think you would need at least 14 GPIO for 10 outputs plus input, clock, and reset, as they tend to come in even numbers of GPIO. If you can get away with 12 GPIO somehow the SLG46855 is 25 cent programmed for 500, 20 for 3000+: <https://www.dialog-semiconductor.com/products/greenpak/slg47503> <https://www.dialog-semiconductor.com/products/greenpak/slg46855> There's an example of an 8 bit de-serealizer on page 89 here, but you can use more flops and pins obviously, the datasheet says you can have up to 21 DFFs with that one. <https://www.dialog-semiconductor.com/sites/default/files/greenpak_cookbook_interactive_pdf_april_2020.pdf> There's a page on calculating propagation delay here: <https://www.dialog-semiconductor.com/greenpak-application-notes/an-cm-283-propagation-delay-considerations> Input to output delay depends somewhat on the type of IO configured, whether the input is Schmitt trigger and the output is push-pull or open drain, etc..non-Schmitt input to 2x push-pull output delay is listed on the order of 15 ns at 5 volts and in my experience I think that's a conservative estimate.
On 9/4/2021 11:41 PM, bitrex wrote:
> On 9/4/2021 10:26 PM, Rick C wrote: >> On Saturday, September 4, 2021 at 9:13:13 PM UTC-4, bitrex wrote: >>> On 9/4/2021 7:33 PM, John Robertson wrote: >>>> Working on a FPGA project and we need perhaps 30 level shifter gates. >>>> >>>> Anyone work with 3.6 to 5.0 volt interfaces that can recommend any >>>> single part over the rest before I spend a few hours digging through >>>> Digi/Mouser/Newark's inventory? >>>> >>>> In some cases we can get away with resistors, but there is a bit of TTL >>>> level drivers needed. >>>> >>>> Thanks! >>>> >>>> John :-#)# >>> Sounding like a broken record proselytizing these things but a number of >>> the Greenpak SPLCs have dual rails so you can have level-shifted IO of >>> arbitrary configuration, they're pretty cheap in quantity, and the mfgr >>> will program them for you. >>> >>> <https://www.dialog-semiconductor.com/products/greenpak> >>> >>> And you can put some logic in 'em, too! >> >> I'm glad you do keep mentioning them.&nbsp; I believe they are pretty cheap >> in quantity, no?&nbsp; You develop your program and they supply them for >> production already programmed, no?&nbsp; Can they compete with a 10 bit >> shifter that costs a quarter?&nbsp; What's the propagation delay pin to pin >> as buffers? >> > > > I think the cheapest device with the capability to 10 bit de-serialize > (if that's what you mean would be the SLG47503, 30 cents programmed in > quantities of 500, 25 cents in quantities of 3000+. I think you would > need at least 14 GPIO for 10 outputs plus input, clock, and reset, as > they tend to come in even numbers of GPIO. > > If you can get away with 12 GPIO somehow the SLG46855 is 25 cent > programmed for 500, 20 for 3000+:
And if you need 10,000+ looks like they'd likely be amenable to go even lower than that.