LE915Ax-P
Hardware Design Guide
1VV0301680 Rev. 2
Page 17 of 51
2021-10-04
Not Subject to NDA
1.8V Power Output
The pad, 1V8_D, is a reference voltage output for IOs. It can be used to provide 1.8V power
to small devices up to 50mA max.
Table 11
:
1.8V power output
General Design Rule
The main guidelines for the Power Supply Design include three different design steps:
•
the electrical design of the power supply
•
the thermal design
•
the PCB layout
4.4.1.
Electrical Design Guidelines
The electrical design of the power supply strongly depends on the power source where
this power is drained.
4.4.1.1.
+5V Source Power Supply Design Guidelines
•
The desired output for the power supply is 3.8V, so there's not a big difference
between the input source and the desired output and a linear regulator can be
used. A switching power supply will not be suitable due to the low drop out
requirements.
•
When using a linear regulator, a proper heat sink shall be provided in order to
dissipate the power generated.
•
A Bypass low ESR capacitor of adequate capacity must be provided in order to cut
the current absorption peaks close to the Module, a 100
μ
F capacitor is usually
suitable.
•
Make sure the low ESR capacitor on the power supply output rated at least 10V.
•
A protection diode must be inserted close to the power input to protect Telit
module from power polarity inversion and/or EOS.
Pin
Signal
I/O
Min (V)
Typical (V)
Max (V)
62
1V8_D
-
1.71
1.8
1.89
