Telit Wireless Solutions SL869T3-I, Руководство пользователя

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SL869T3-I Product User Guide
1VV0301546 Rev. 3
Page 29 of 68 2021-03-31
The external DC voltage supply (including regulators, capacitors, etc.) must be designed
to ensure that stable power is maintained within the specifications listed below.
The supply voltage must be within specification within 10 milliseconds of initial
application.
The power-up sequence must not be interrupted for at least one second or the module
may fail to start up. If the module does not initialize correctly due to improper application
of VCC, the module can be reset by:
•
Removing power from both Vcc and Vbatt and then reapplying it in the proper
manner or,
•
Asserting the nRESET pin (low).
Hold pins 3, 14, and 20 low for 1 second or the start of the first output message.
See section
8.5.3 DC Power Requirements
for power specifications.
Pin 9 is connected to pin 23 by an internal trace and may (optionally) be connected to the
external supply for pin 23.
8.5.2. VBATT
The Battery Backup supply voltage is used to power the RTC and BBRAM domains. It
maintains critical data to enable HOT and WARM starts.
Internal diode OR’ing provides an internal source for VBATT even if this pin is not used.
Vbatt must be less than Vcc to ensure that Vbatt current does not rise excessively during
normal operation (that is when Vcc is applied),
An internal reset of the module is generated upon removal and reapplication of VBATT
(not VCC).
If the module does not initialize correctly due to improper application of VCC_IN, the
module can be reset by:
•
Removing power from both Vcc and Vbatt and then reapplying it in the proper
manner or,
• Asserting the nRESET pin (low).
See section
8.5.3 DC Power Requirements
for power specifications.
8.5.3. DC Power Requirements
Name Min Typ Max Units