Datasheet

Data Sheet ADF4360-3
Rev. D | Page 17 of 24
Hardware Power-Up/Power-Down
If the part is powered down via the hardware (using the CE pin)
and powered up again without any change to the N counter
register during power-down, the part locks at the correct fre-
quency because the part is already in the correct frequency
band. The lock time depends on the value of capacitance on the
C
N
pin, which is <5 ms for 10 µF capacitance. The smaller ca-
pacitance of 440 nF on this pin enables lock times of <600 µs.
The N counter value cannot be changed while the part is in
power-down, since the part may not lock to the correct fre-
quency on power-up. If it is updated, the correct programming
sequence for the part after power-up is to the R counter latch,
followed by the control latch, and finally the N counter latch,
with the required interval between the control latch and N
counter latch, as described in the Initial Power-Up section.
Software Power-Up/Power-Down
If the part is powered down via the software (using the control
latch) and powered up again without any change to the N coun-
ter latch during power-down, the part locks at the correct fre-
quency because the part is already in the correct frequency
band. The lock time depends on the value of capacitance on the
C
N
pin, which is <5 ms for 10 µF capacitance. The smaller ca-
pacitance of 440 nF on this pin enables lock times of <600 µs.
The N counter value cannot be changed while the part is in
power-down because the part may not lock to the correct fre-
quency on power-up. If it is updated, the correct programming
sequence for the parts after power-up is to the R counter latch,
followed by the control latch, and finally the N counter latch,
with the required interval between the control latch and N
counter latch, as described in the Initial Power-Up section.