Making my own buffer circuit

[drakejest]

So i am in need of a 50mA single channel buffer circuit, since i could not find one i was thinking of making my own push-pull using this N - P channel mosfet SIA517. My input logic is 3v3 volts and will be pushing/pulling 5v.

Can i do it this way>? am i missing something important that are present in those timeless classics such as 74LVC/74AHCT ?

 

[magic]

Two problems with a discrete solution:
- potential crossconduction when the input is at 50%
- the P-ch will always see at least -1.7V at its gate
This may work if the FETs have high enough threshold voltage (like >2.5V) and still enough conductance at Vgs=3.3V to drive 50mA.

Possible alternative: something like 74HCT2G04, parallel both sections.

[drakejest]

You probably are missing something in the timeless classics.

Not many of them on a single output pin will both source and sink 50mA and have 3v3 level inputs with 5V outputs,
but some of the up-translation type voltage translators / dual supply buffers may.
Many others can, say, source 32mA and sink 64mA if that helps (unless you need source/sink = 50mA both). 

Or you can parallel-connect two (or three) of the single-channel devices so that each only needs somewhat more than 25x2 / (17x3) mA output capability or less.

For instance:
https://www.ti.com/product/SN74LVC1T45

Voltage Level Translation Guide - TI.com
https://www.ti.com/lit/ml/scyb018h/scyb018h.pdf

Voltage Translation Buying Guide (Rev. A) - ti.com
https://www.ti.com/lit/sg/slyy165a/slyy165a.pdf

Logic Guide (Rev. AB) - Texas Instruments
https://www.ti.com/lit/sg/sdyu001ab/sdyu001ab.pdf

Little Logic Guide - TI.com
https://www.ti.com/lit/sg/scyt129g/scyt129g.pdf

LITTLE LOGIC SELECTION GUIDE - Texas Instruments
https://www.ti.com/pdfs/logic/littlelogicsg.pdf

https://www.ti.com/logic-voltage-translation/overview.html

So i am in need of a 50mA single channel buffer circuit, since i could not find one i was thinking of making my own push-pull using this N - P channel mosfet SIA517. My input logic is 3v3 volts and will be pushing/pulling 5v.

Can i do it this way>? am i missing something important that are present in those timeless classics such as 74LVC/74AHCT ?

I have a 1nF line capacitance that i need to overcome, thats why i need such a high current buffer. Paralleling buffers feels not right.

[drakejest]

Two problems with a discrete solution:
- potential crossconduction when the input is at 50%
- the P-ch will always see at least -1.7V at its gate
This may work if the FETs have high enough threshold voltage (like >2.5V) and still enough conductance at Vgs=3.3V to drive 50mA.

Possible alternative: something like 74HCT2G04, parallel both sections.

You probably are missing something in the timeless classics.

Not many of them on a single output pin will both source and sink 50mA and have 3v3 level inputs with 5V outputs,
but some of the up-translation type voltage translators / dual supply buffers may.
Many others can, say, source 32mA and sink 64mA if that helps (unless you need source/sink = 50mA both). 

Or you can parallel-connect two (or three) of the single-channel devices so that each only needs somewhat more than 25x2 / (17x3) mA output capability or less.

For instance:
https://www.ti.com/product/SN74LVC1T45

Voltage Level Translation Guide - TI.com
https://www.ti.com/lit/ml/scyb018h/scyb018h.pdf

Voltage Translation Buying Guide (Rev. A) - ti.com
https://www.ti.com/lit/sg/slyy165a/slyy165a.pdf

Logic Guide (Rev. AB) - Texas Instruments
https://www.ti.com/lit/sg/sdyu001ab/sdyu001ab.pdf

Little Logic Guide - TI.com
https://www.ti.com/lit/sg/scyt129g/scyt129g.pdf

LITTLE LOGIC SELECTION GUIDE - Texas Instruments
https://www.ti.com/pdfs/logic/littlelogicsg.pdf

https://www.ti.com/logic-voltage-translation/overview.html

So i am in need of a 50mA single channel buffer circuit, since i could not find one i was thinking of making my own push-pull using this N - P channel mosfet SIA517. My input logic is 3v3 volts and will be pushing/pulling 5v.

Can i do it this way>? am i missing something important that are present in those timeless classics such as 74LVC/74AHCT ?

The TI guide although were helpful, but i did not quite get the perfect chip. They all need me to shift the voltage up before i can use them. Till i found this chip 74ABT244. No need to to shift the voltage up as its 5v vcc it only needs 2v Vhight. Its also 8 CHANNELS. I will parallel 4 of those each capable of 32mA. This is the chosen one ! haha.

What do you think?