Ublox TOBY-R2 Series System Integration Manual

Also see for TOBY-R2 Series: User guide

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Ublox TOBY-R2 Series System Integration Manual Manual pdf 116 page image

TOBY-R2 series - System integration manualUBX-16010572 - R10 Design-in Page 116 of 1512.8 General Purpose Input/Output2.8.1.1 Guidelines for GPIO circuit designA typical usage of TOBY-R2 series modules’ GPIOs can be the following: Network indication provided over GPIO1 pin (see Figure 65 / Table 49 below) GNSS supply enable function provided by the GPIO2 pin (see section 2.6.3) GNSS Tx data ready function provided by the GPIO3 pin (see section 2.6.3) GNSS RTC sharing function provided by the GPIO4 pin (see section 2.6.3) SIM card detection provided over GPIO5 pin (see Figure 48 / Table 38 in section 2.5)TOBY-R2 seriesGPIO1R1R33V8Network IndicatorR221DL1T1Figure 65: Application circuit for network indication provided over GPIO1Reference Description Part Number - ManufacturerR1 10 k Resistor 0402 5% 0.1 W Various manufacturersR2 47 k Resistor 0402 5% 0.1 W Various manufacturersR3 820  Resistor 0402 5% 0.1 W Various manufacturersDL1 LED Red SMT 0603 LTST-C190KRKT - Lite-on Technology CorporationT1 NPN BJT Transistor BC847 - InfineonTable 49: Components for network indication application circuit☞ Use transistors with at least an integrated resistor in the base pin or otherwise put a 10 k resistoron the board in series to the GPIO of TOBY-R2 series modules.☞ Do not apply voltage to any GPIO of the module before the switch-on of the GPIOs supply (V_INT),to avoid latch-up of circuits and allow a proper module boot. If the external signals connected tothe module cannot be tri-stated or set low, insert a multi channel digital switch (e.g. TISN74CB3Q16244, TS5A3159, TS5A63157) between the two-circuit connections and set to highimpedance before V_INT switch-on.☞ ESD sensitivity rating of the GPIO pins is 1 kV (Human Body Model according to JESD22-A114).Higher protection level could be required if the lines are externally accessible and it can be achievedby mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor array) close to accessiblepoints.☞ If the GPIO pins are not used, they can be left unconnected on the application board.2.8.1.2 Guidelines for general purpose input/output layout designThe general purpose inputs / outputs pins are generally not critical for layout.