Level Shifter, how to minimize power dissipated

Question

In the above circuit used as level shifter, I would like to know if

1. Changing all Resistances by a factor of 10 would still give the same result. The reason I'd like to increase the resistances is to make sure that a minimal amount of current actually flows.
2. If R1 is really needed.

Any other level shifter which is more efficient using transistors/cap/res? I unfortunately am not from this background, so circuits using MOSFET goes over my head. However if some description is given, I'll be grateful.

Answer 1

If you really want to save power, you can use a 5 V CMOS buffer with TTL input levels, like 74AHCT1G125.

The input switching threshold is between 0.8 and 2.0 V, nicely compatible with 3.3 V TTL or CMOS levels.

The quiescent current is around 10 uA.

And if you put any value on assembly time, or you're paying per location for pick and place, it will likely work out cheaper than a discrete solution.