u-blox JODY-W2, Руководство по системной интеграции

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JODY-W2 - System integration manual
UBX-18068879 - R14 System description Page 18 of 84
C1 - Public
Name I/O Description Remarks
LPO_IN I 32.768 kHz clock input Failsafe pin.
Table 13: External 32.768 kHz sleep clock signal description
LPO_IN is a failsafe input, clock signal that can be applied to the pin when the module is not powered
and the requirements in Table 14 are fulfilled.
☞
Not applicable for automotive grade module variants.
Parameter LPO clock Unit
Nominal input frequency 32.768 kHz
Frequency accuracy ±250 ppm
Duty cycle 30 – 70 %
Input signal accuracy 200 – 3300 mV, pkpk
Signal type Square-wave or Sine-wave -
Input impedance 3 > 100
kΩ
< 5 pF
Clock jitter (during startup) < 10,000 ppm
Table 14: External 32.768 kHz sleep clock specification
JTAG – Test Interface
A JTAG test interface is supported on chipset pins GPIO14 – 17. Table 15 shows the mapping between
chipset and module pins.
Chip pin name Module pin name Supply domain Description
GPIO_14 GPIO_14 VIO JTAG_TCK test clock (Input)
GPIO_15 GPIO_15 VIO JTAG_TMS controller select (Input)
GPIO_16 LTE_COEX_RX VIO UART_LTE_SIN / JTAG_TDI test data input (Input)
GPIO_17 LTE_COEX_TX VIO UART_LTE_SOUT / JTAG_TDO test data output (Output)
Table 15: JTAG signal mapping
1.5 Antenna interfaces
Wi-Fi and Bluetooth antennas
JODY-W2 provides two antenna pins, one for dual-band Wi-Fi connectivity ( ANT1 ) and another for
Bluetooth ( ANT0 ). The following recommendations apply to developing an antenna interface for the
JODY-W2 module:
• Where possible, consider integrating in the end product the u-blox reference design to minimize
the effort on the certification process. For the full list of available reference designs, see the
JODY-W2 antenna reference design, application note
[15].
• The ANT0 and ANT1 pins of JODY-W2 have a nominal characteristic impedance of 50  and must
be connected to the external antennas through a 50  transmission line to allow proper RF
transmission and reception.
• Good isolation must be provided between the various antennas in the system. Special care shall be
taken to maximize isolation between the antennas operating in the same or nearby bands.
For information describing how to properly design circuits compliant with these requirements, see
Antenna interfaces .
3
When power is applied or switched off.