I have occasions where I need to drive 5V hardware, and I'd also like to work more with ARMs, which, with a few exceptions, top out at 3.3V. So what are some standard translator chips that can take 3.3V in and output 5V? Maybe single drivers in a small transistor-like package, as well as chips with more drivers. Maybe just 5V buffers with TTL- compatible input levels, so 2.4V for a '1', are there such single or double buffers in a small package? Thanks for any pointers.
What's a good level translator from 3.3V to 5V? Either single drivers or multiples.
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A simple FET or transistor works well, otherwise something like SN74LVC1G126 or 74HC/HCT365
TI has a bunch of them. Never used them, but have looked in some detail.
Jim
ghjk
Last Edited: Mon. Jun 24, 2019 - 08:27 AM
There are endless level shifters of all types. Right here I have an MPLAB Snap programmer, it uses a bunch of 74LVC1T45 from Nexperia.
I also have a cheap 8 channel level shifter from Aliexpress. This one uses the TXS0108E from TI.
And the simple MOS level shifter has already been mentioned.
If I need a bidirectional level shifter I tend to use the TXS010x family from TI. Available in reasonable SMT packages, like SOT23 (6 pin) and MSOP8.
If you want a 5V ARM, try the ATSAMC21 family. Cortex-M0+ core, essentially a clone of the SAMD21 (so lots of Arduino-ish code) plus 5V operation, a faster ADC, CAN, and a few other additions.
El Tangas wrote:
There are endless level shifters of all types
That's why I thought I'd ask first. :)
There are so many because there are different requirements:
- unidirectional
- bidirectional
- open collector - good for I2C
- three state output with output enable that you can connect multiple outputs to one line like MISO line from multiple SPI slaves
- converting up
- converting down
- TTL, CMOS, Schmitt input
- VCC range
- speed
- fanout
- package
- temperature
- whether the output can be driven while not powered
and obviously the price
Digikey has nice filters on them. Arduino hardware is also a good place to start looking for them.
One of the critical parameters for bidirectional devices is "turn-around time". Not much of an issue for slowest speed I2C but it gets more important as the clock rate goes up.
Jim
I think I found what I needed, a single-gate 74AHCT part. Works on 5V and the T means TTL-level inputs, so 2V for a '1', thus compatible with a 3.3V driving signal. And I found them for a nickel each, and who doesn't love a bargain?
Some of us here remember when there were only three 74xxx families: 74xxx, 74Sxxx and 74LSxxx. Now it looks as though there are 300 families!
Thanks to all for the replies.
ghjk
Last Edited: Mon. Jun 24, 2019 - 08:27 AM