TOBY-L1 and MPCI-L1 series - System Integration Manual
UBX-13001482 - R04
Advance Information
System description
Page 21 of 90
1.5.2
RTC supply output (V_BCKP)
V_BCKP
output pin is not accessible on MPCI-L1 series modules.
The
V_BCKP
output pin of the TOBY-L1 series module is connected to an internal 2.5 V supply with low current
capability (refer to
[1]). This supply is internally generated by a linear LDO regulator
integrated in the Power Management Unit, as shown in Figure 7. The output of this regulator is always enabled
when the main module voltage supply applied to the
VCC
pins is within the valid operating range.
Baseband
Processor
70
VCC
71
VCC
72
VCC
3
V_BCKP
Linear
LDO
Power
Management
TOBY-L1 series
32 kHz
RTC
Figure 7: TOBY-L1 modules’ RTC supply output (V_BCKP) simplified block diagram
1.5.3
Generic digital interfaces supply output (V_INT)
V_INT output pin is not accessible on MPCI-L1 series modules.
The
V_INT
output pin of the TOBY-L1 series module is connected to an internal 1.8 V supply with current
capability (refer to
[1]). This supply is internally generated by a switching step-down
regulator integrated in the Power Management Unit and it is internally used to source the digital I/O interfaces of
the TOBY-L1 series module, as described in Figure 8. The output of this regulator is enabled when the module is
switched on and it is disabled when the module is switched off.
Baseband
Processor
70
VCC
71
VCC
72
VCC
5
V_INT
Switching
Step-Down
Power
Management
TOBY-L1 series
Digital I/O
Figure 8: TOBY-L1 modules’ generic interfaces supply output (V_INT) simplified block diagram
The switching regulator operates in Pulse Width Modulation (PWM) mode for greater efficiency at high output
loads and it automatically switches to Pulse Frequency Modulation (PFM) power save mode for greater efficiency
at low output loads.