Correct voltage translator

[Vindhyachal.takniki]

1. I have a motor encode with max speed = 6000 rpm & 3600 pulses at each revolution.
So max freq = 6000*3600 = 21.6Mhz.
2. Encode is powered by 10-30V dc. But MCU is powered by 3.3V.
3. So I need to step down the voltage of encoder pulses.
4. Currently encoder is powered by 10V. I have a placed a small resistor & 3.6V zener. I am getting step down voltage but there is some rise & fall of pulse at across zener, which I see is comparable when I compare encoder output & zener out.

5. I can use either optocoupler or any buffer IC for this.
6. I had looked at FOD8001, 25Mhz, but it require Vcc at input also. and max is 3.3 or 5V only.
ICPL2631 is 10Mhz.
7. Avago HCPL-0720, is good, but it require VCC at input with max of 6V. I need to place some regulator for powering input vdd also.

8. Any other product fit for this?

[bktemp]

1. I have a motor encode with max speed = 6000 rpm & 3600 pulses at each revolution.
So max freq = 6000*3600 = 21.6Mhz.

rpm = per minute, so you only have 360kHz not 21.6MHz.

[Vindhyachal.takniki]

Sry its 360khz

[Rerouter]

Here you go, a cut back version of the input on a frequency counter project of mine, it ensures you get an accurate representation of the rising and falling edges even when the circuit does not get close to ground,