Datasheet
LPC540xx All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2018. All rights reserved.
Product data sheet Rev. 1.8 — 22 June 2018 115 of 168
NXP Semiconductors
LPC540xx
32-bit ARM Cortex-M4 microcontroller
[1] Data based on characterization results, not tested in production.
[2] Excluding under- and overshoot which may occur when the PLL is not in lock.
[3] A phase difference between the inputs of the PFD (clkref and clkfb) smaller than the PFD lock criterion
means lock output is HIGH.
[4] Actual jitter dependent on amplitude and spectrum of substrate noise.
[5] Input clock coming from a crystal oscillator with less than 250 ps peak-to-peak period jitter.
11.7 FRO
The FRO is trimmed to 1 % accuracy over the entire voltage and temperature range.
[1] Typical ratings are not guaranteed. The values listed are at room temperature (25 C), nominal supply
voltages.
11.8 Crystal oscillator
Table 33. Dynamic characteristics of the PLL2
[1]
Symbol Parameter Conditions Min Typ Max Unit
Reference clock input
F
in
input frequency 1 - 25 MHz
Clock output
f
o
output frequency for PLL2 clkout
output
[2]
4.3 - 550 MHz
d
o
output duty cycle for PLL2 clkout
output
46 - 54 %
f
CCO
CCO frequency 275 - 550 MHz
Lock detector output
lock(PFD)
PFD lock criterion
[3]
124 ns
Dynamic parameters at f
out
= f
CCO
= 540 MHz; standard bandwidth settings
J
rms-interval
RMS interval jitter f
ref
= 10 MHz
[4][5]
-1530 ps
J
pp-period
peak-to-peak, period
jitter
f
ref
= 10 MHz
[4][5]
-4080 ps
Table 34. Dynamic characteristic: FRO
T
amb
=
40
C to +105
C; 1.71 V
V
DD
3.6 V.
Symbol Parameter Conditions Min Typ
[1]
Max Unit
f
osc(RC)
FRO clock frequency - 11.88 12 12.12 MHz
f
osc(RC)
FRO clock frequency - 47.52 48 48.48 MHz
f
osc(RC)
FRO clock frequency - 95.04 96 96.96 MHz
Table 35. Dynamic characteristic: oscillator
T
amb
=
40
C to +105
C; 1.71 V
V
DD
3.6 V.
[1]
Symbol Parameter Conditions Min Typ
[2]
Max Unit
Low-frequency mode (1-20 MHz)
[4]
t
jit(per)
period jitter time 5 MHz crystal
[3]
- 13.2 - ps
10 MHz crystal - 6.6 - ps
15 MHz crystal - 4.8 - ps