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?

 

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

Fmax = F*3600=(6000rpm/60s)*3600 = 100Hz*3600=360000Hz=360Khz.

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.

Setup for the voltage of encoder.
Using two resistors to be a voltage divider, and in parallel a 3.6V zener diode with the low resistor, the current of zener should be about 10mA.

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.

Attach a clearly photo of waveform.

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?

Go back to see the first item.

 

hi VT,
At 6000 rpm is that 6000/60secs = 100 revs/sec .???
So 100 * 3600 pps
E