Data Sheet
Table Of Contents
- Document information
- Contents
- 1 Functional description
- 2 Pin definition
- 3 Electrical specifications
- 4 Firmware
- 5 Mechanical specifications
- 6 RF design notes
- 7 BMD-380 evaluation development kit
- 8 Qualification and approvals
- 9 Environmental
- 10 Product handling
- 11 Ordering information
- 12 Life support and other high-risk use warning
- Related documents
- Revision history
- Contact
BMD-380 - Data sheet
UBX-19039467 - R06 Electrical specifications Page 17 of 36
3.7.1 32.768 kHz crystal (LFXO)
Symbol
Parameter
Typ.
Max.
Unit
F
NOM_LFXO
Crystal frequency
32.768
-
kHz
F
TOL_LFXO_BLE
Frequency tolerance, Bluetooth low energy
applications
3
-
±500
ppm
f
TOL_LFXO_ANT
Frequency Tolerance, ANT applications
4
-
±50
ppm
C
L_LFXO
Load Capacitance
-
12.5
pF
C
0_LFXO
Shunt Capacitance
-
2
pF
R
S_LFXO
Equivalent series resistance
-
100
kΩ
C
pin
Input Capacitance on XL1 & XL2 pads
4
-
pF
Table 9: 32.768 kHz crystal (LFXO)
3.7.2 32.768 kHz clock source comparison
Symbol
Parameter
Min.
Typ.
Max.
Unit
I
LFXO
Current for 32.768 kHz Crystal Oscillator
-
0.23
-
µA
I
LFRC
Current for 32.768 kHz RC Oscillator
-
0.7
1
µA
I
LFSYNT
Current for 32.768 kHz Synthesized Oscillator
-
100
-
µA
f
TOL_LFXO_BLE
Frequency Tolerance, 32.768 kHz Crystal Oscillator (Bluetooth low
energy Stack)
3
-
-
±500
ppm
f
TOL_LFXO_ANT
Frequency Tolerance, 32.768 kHz Crystal Oscillator (ANT Stack)
4
-
-
±50
ppm
f
TOL_LFRC
Frequency Tolerance, 32.768 kHz RC Oscillator
-
-
±5
%
f
TOL_CAL_LFRC
Frequency tolerance, 32.768 kHz RC after calibration
-
-
±500
ppm
f
TOL_LFSYNT
Frequency Tolerance, 32.768 kHz Synthesized Oscillator
-
-
±48
ppm
Table 10: 32.768 kHz clock source comparison
3
f
TOL_LFXO_BLE
and f
TOL_LFXO_ANT
are the maximum allowed for Bluetooth low energy and ANT applications. Actual tolerance
depends on the crystal used.
4
The ANT protocol requires the use of an external crystal.