Simple 5V to 3.3V level converter for an ICD2 clone (Untested)

blueroomelectronics

Well-Known Member

• Aug 18, 2007

• #1

Came across this simple level converter for programming 3.3V chips with a 5V programmer but have yet to try it myself, looks like it might work.
Comments?
**broken link removed**

 

P

pc88

New Member

• Aug 18, 2007

• #2

Looks pretty slick. Took me a while to figure out that PGD/DATA are bi-directional lines, right?

 

blueroomelectronics

Well-Known Member

• Aug 18, 2007

• #3

Yep PGD is bidirectional, but the clock PGC isn't.

 

justDIY

Active Member

• Aug 19, 2007

• #4

how is the circuit with double transistors and four resistors better or worse than this level shifter with two resistors and one transistor?

**broken link removed**
image borrowed from sparkfun

That circuit, provided by Sparkfun, was (possibly) originally suggested in Philips AN97055 "Bi-Directional Level Shifting for i2c bus and other systems", pictured below.

 

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Mike - K8LH

Well-Known Member

• Aug 19, 2007

• #5

That's more like it. I was thinking it might be possible to use a single MOSFET.