Datasheet

ADF4360-8
Rev. A | Page 18 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 <15 ms for 10 µF capacitance. The smaller
capacitance 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
frequency on power-up. If it is updated, the correct program-
ming sequence for the part after power-up is 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
counter latch during power-down, the part locks at the correct
frequency, 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 <15 ms for 10 µF capacitance. The smaller
capacitance 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
frequency on power-up. If it is updated, the correct program-
ming 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.