TOBY-L4 series - System Integration Manual
UBX-16024839 - R04
System description
Page 31 of 143
1.6
System function interfaces
1.6.1
Module power-on
TOBY-L4 series modules can be switched on in the following way:
Low pulse on the
PWR_ON
pin, which is normally set high by an internal pull-up, for a valid time period,
when the applied
VCC
voltage is stable at its nominal value within the valid operating range.
As illustrated in Figure 12, the TOBY-L4 series
PWR_ON
input is equipped with an internal active pull-up resistor
to an internal 1.3 V supply rail: the
PWR_ON
input voltage thresholds are different from the other generic digital
interfaces, and the line should be driven by an open drain, by an open collector or by a contact switch, without
an external pull-up resistor.
Detailed electrical characteristics and specifications are described in
TOBY-L4 series
Data Sheet
Baseband
Processor
20
PWR_ON
TOBY-L4 series
Power-on
Power
Management
Power-on
35k
1.3 V
Figure 12: TOBY-L4 series PWR_ON input description
TOBY-L4 series modules do not switch on by applying the
VCC
supply only: a low pulse must be forced on
the
PWR_ON
pin when the
VCC
voltage is stable at its nominal value within the valid operating range.