Ublox TOBY-R2 Series, System Integration Manual

Page: 26 / 151

TOBY-R2 series - System integration manual
UBX-16010572 - R10 System description Page 26 of 151
1.6 System function interfaces
1.6.1 Module power-on
When the TOBY-R2 series modules are in the not-powered mode (switched off, i.e. the VCC module
supply is not applied), they can be switched on as following:

Rising edge on the VCC input to a valid voltage for module supply, i.e. applying module supply: the
modules switch on if the VCC supply is applied, starting from a voltage value of less than 2.1 V,
with a rise time from 2.3 V to 2.8 V of less than 4 ms, reaching a proper nominal voltage value
within VCC operating range.
Alternately, in case for example the fast rise time on VCC rising edge cannot be guaranteed by the
application, TOBY-R2 series modules can be switched on from not-powered mode as following:
 RESET_N input pin is held low by the external application during the VCC rising edge, so that the
modules will switch on when the external application releases the RESET_N input pin from the low
logic level after that the VCC supply voltage stabilizes at its proper nominal value within the
operating range
 PWR_ON input pin is held low by the external application during the VCC rising edge, so that the
modules will switch on when the external application releases the PWR_ON input pin from the low
logic level after that the VCC supply voltage stabilizes at its proper nominal value within the
operating range
When the TOBY-R2 series modules are in the power-off mode (i.e. switched off with valid VCC module
supply applied), they can be switched on as following:
 Low pulse on the PWR_ON pin, which is normally set high by an internal pull-up, for a valid time
period: the modules start the internal switch-on sequence when the external application releases
the PWR_ON pin from the low logic level after that it has been set low for an appropriate time
period
 Rising edge on the RESET_N pin, i.e. releasing the pin from the low level, as that the pin is normally
set high by an internal pull-up: the modules start the internal switch-on sequence when the
external application releases the RESET_N pin from the low logic level

RTC alarm, i.e. pre-programmed alarm by AT+CALA command (see u-blox AT commands
manual
[2] ).
As described in Figure 13 , the TOBY-R2 series PWR_ON input is equipped with an internal active
pull-up resistor to the V_BCKP supply: the PWR_ON input voltage thresholds are different from the
other generic digital interfaces. Detailed electrical characteristics are described in TOBY-R2 series
data sheet
[1] .
Baseband
processor
20
PWR_ON
TOBY-R2 series
3
V_BCKP
Power-on
Power
management
Power-on
10k
Figure 13: TOBY-R2 series PWR_ON input description