hi,
I am designing auto ranging frequency meter
Measurment scheme :
using timer0 in counter mode for period
limited by timer 1 in timer mode .It is 100ms for freq ranges 10MHz-10Hz & 1sec for 1Hz-9.999Hz.
Ckt consist of pll4046 for multiplication in lower range & modulo 10 counters

problem with ckt. is frequency change from MHz range to
Hz range, ckt takes almost 6 Sec to respond to this change.

LP Filter capacitor with pll affects this period much but it can not be decreased below 10uf

I need help!

thank you