Data Sheet

BLM01 - Data she
et
Page 11 of 15
H
ynall
Intell
igent Control Co., Ltd
3.7.1 32.768 kHz crystal (LFXO
)
Symbol Parameter Typ. Max. Unit
F
NOM_LFXO
Crystal fre
quency
32.768 - kHz
F
TOL_LFXO_BLE
Frequency tol
erance, Bluetooth low energy applications
1
- ±250 ppm
f
TOL_LFXO_A
NT
Frequency Tole
rance, ANT applications
1
- ±50 ppm
C
L_LFXO
L
o
a
d
ca
p
a
ci
t
a
nce
- 12.
5
pF
C
0_LFXO
Shunt capacitance - 2 pF
R
S_LFXO
Equivalent
series resistance
- 100 k Ω
C
pin
Input capacit
ance on XL1 & XL2 pads
4 - pF
Notice:
1: f
TOL_LFXO_BLE
and f
TOL_LFXO_ANT
are the maximum allow
ed for Bluetooth low energy and ANT applications. Actual
tolerance
depends on the crystal used.
Table 6: 32.768 kHz cr
ystal (LFXO)
3.7.2 32.768 kHz clock sour
ce comparison
Symbol Parameter Min. Typ. Max. Unit
I
LFXO
Current for 32.
768 kHz Crystal oscillator
- 0.25 - µA
I
LFRC
Current for 32.
768 kHz RC oscillator
- 0.6 1 µA
I
LFSYNT
Current for 32.
768 kHz Synthesized oscillator
- 100 - µA
f
T
O
L_
LF
X
O
_
B
L
E
Fr
e
q
ue
n
cy T
o
l
e
r
ance, 32.768 kHz Crystal oscillator (Bluetooth low
energy Stack)
1
- - ±
25
0 p
p
m
f
TOL_LFXO_A
NT
Frequency Toler
ance, 32.768 kHz Crystal oscillator (ANT Stack)
1
- - ±50 ppm
f
T
O
L_
LF
R
C
Frequency Tole
rance, 32.768 kHz RC oscillator
- - ±2 %
f
TOL_CAL_LFRC
Frequency toler
ance, 32.768 kHz RC after calibration
- - ±250 ppm
f
TOL_LFSYNT
Frequency Toler
ance, 32.768 kHz Synthesized oscillator
- - ±48 ppm
Notice:
f
TOL_LFXO_BLE
and f
TOL_LFXO_ANT
are the maximum allowe
d for Bluetooth low energy and ANT applications. Actual
tolerance
depends on the crystal used.
T
abl
e 7:
32.
76
8 k
H
z
c
l
ock source comparison