Ublox LISA-U1 Series System Integration Manual

Also see for LISA-U100: Integration manual

Contents

Ublox LISA-U1 Series System Integration Manual Manual pdf 29 page image

LISA-U1 series - System Integration Manual3G.G2-HW-10002-3 Preliminary System descriptionPage 29 of 125ACTIVE MODE20-25 mA20-25 mA2G case: 0.47-2.12 s3G case: 0.64-5.12 sPaging periodTime [s]Current [mA]150100500Time [ms]Current [mA]15010050020-25 mARXEnabledDSPEnabled35-40 mA2G case: ~125 mA3G case: ~110 mA2G case: ~125 mA3G case: ~110 mAFigure 14: Description of the VCC current consumption profile versus time when power saving is disabled: active-mode isalways held, and the receiver and the DSP are periodically activated to monitor the paging channel for paging block reception1.5.4 RTC Supply (V_BCKP)The V_BCKP pin connects the supply for the Real Time Clock (RTC) and Power On / Reset internal logic. Thissupply domain is internally generated by a linear regulator integrated in the Power Management Unit. Theoutput of this linear regulator is always enabled when the main voltage supply provided to the module throughVCC is within the valid operating range, with the module switched-off or powered-on.Name Description RemarksV_BCKP Real Time Clock supply V_BCKP = 2.3 V (typical) generated by the module to supplyReal Time Clock when VCC supply voltage is within validoperating range.Table 8: Real Time Clock supply pinThe V_BCKP pin ESD sensitivity rating is 1 kV (Human Body Model according to JESD22-A114F). Higherprotection level could be required if the line is externally accessible on the application board. Higherprotection level can be achieved by mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistorarray) on the line connected to this pin.The RTC provides the time reference (date and time) of the module, also in power off mode, when the V_BCKPvoltage is within its valid range (specified in u-blox LISA-U1 series Data Sheet [1]). The RTC timing is normally