Data Sheet

30
3.7 Sleep Clock
An external crystal is used for generating all radio frequencies and normal operation clocking. As an
alternative, an external frequency reference driven by a temperature-compensated crystal oscillator
(TCXO) signal may be used. No software settings are required to differentiate between the two. In
addition, a low-power oscillator (LPO) is provided for lower power mode timing.
External 32.768KHz Low-Power Oscillator
Symbol
Parameter
Min
Typ
Max
Units
CLK
Clock frequency range/ accuracy
 CMOS input clock signal type
 ±250 ppm (initial, aging,
temperature)
-
32.768
-
kHz
PN
Phase noise requirement (@ 100KHz)
-
-125
-
dBc/Hz
J
C
Cycle jitter
-
1.5
-
ns
(RMS)
SR
Slew rate limit (10-90%)
-
-
100
ns
DC
Duty cycle tolerance
20
-
80
%