high to low voltage CMOS level shifter circuit

[viperpaki007]

Hi,

I am looking for a high to low level CMOS level shifter. Can somebody refer some circuit.

regards

 

[KlausST]

Hi,

a more detailed description please.

Voltage levels, supply voltage, speed, logic diagram.. all you can provide.

Klaus

 

[viperpaki007]

My input clock signal has 3.6V and 1.8V logic and i need to convert this clock to 1.8V and 0V logic. Clock frequency is around 350MHz.

 

[KlausST]

Hi,

Do you mean input signal: high = 3.6V, low = 1.8V?
==> don't know any Cmos family with low = 1.8 V.
If this really is your signal, then a high speed comparator with logic level output may help.

For 3.3V LVCmos to 1.8V LVCmos there are buffers with 1.8V Vcc and 3.3V input tolerance.

Klaus

 

[csolis_GT]

It seems that you need two level shifters:

1st one converts the signal to a 3.6 - 0 V logic signal. You can use cross-coupled NMOS level shifter.
2nd would be the same but PMOS version to bring the 3.6 V high level back to 1.8 V.

I should advice you that the 1st level shifter's transistor should have a breakdown voltage of 3.6 V, or you have to be creative using 1.8 V transistors by stacking them so each one see a maximum of 1.8 V.