N58 Hardware User Guide
Chapter 5 Application Interfaces
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59
Figure 5-34 Reference design of forcible download
N58 Module
USB_ BOOT
VDD_1P8
1k
Ω
10k
Ω
R1
R2
S1
D1
5.6.5 VBACKUP and VRTC
Pin Name
Pin No.
I/O
Function
Remarks
VBACKUP
105
PI
GNSS backup power supply
-
VRTC
113
PI
RTC power supply
-
VBACKUP mainly provides power supply for RTC and backup RAM of GNSS circuits. The voltage
range is 3.0 V to 3.3 V. Leave this pin floating if it is not used. To use the hot start function of GNSS
and save the positioning data, connect it to a backup power supply or keep continuous power supply.
Otherwise, GNSS is cold started every time.
VRTC is the backup power pin of N58 module RTC and can be connected to a coin battery or farad
capacitor. It can provide short-term power supply to keep the RTC working after the VBAT is
disconnected. The power supply range is 2.8 V to 3.2 V, and the typical value is 3 V.
The following figure shows the reference design of VBACKUP and VRTC power supply.