Re: Low Zener Voltage?



eromlignod wrote:

Hi Guys:

This is a simple one. I've got a 0 to 5V square wave that I want to
convert to a 0 to 3.3V square wave. I tried putting a series resistor
and a 3.3V zener diode to ground.

The wave stays nice and square, but it comes out as 0 to 2.0 volts. I
have tried varying the value of the resistor, but it doesn't help.
What am I doing wrong? Is there a better way to do what I'm trying to
do?

Zeners are very 'sloppy' at regulating voltages. You're putting too little
current through the zener.

An 'active clamp' is perhaps the best answer (or a dedicated buffer for voltage
translation) but do you need to implement this with very few parts ?

Graham

.

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  • Low Zener Voltage?
    ... I've got a 0 to 5V square wave that I want to ... I tried putting a series resistor ... The wave stays nice and square, but it comes out as 0 to 2.0 volts. ... have tried varying the value of the resistor, ...
    (sci.electronics.basics)