Main Power Supply (Vdd); Mcu Flash Programming (Vpp); Figure 3. Power Supplies Pcb Area - ST EVALCOMMBOARD Manual

Power supply
Figure 3.
2.1 Main power supply (V
The main power supply system of Industrial Com Board consists of a DC-DC switching
converter based on step-down regulator L5973 from ST. The switching regulator is designed
to provide 5V (V
assembled in the two following configurations:
●
Buck: referring to
with a short
● Buck-Boost (not optimized)
2.2 MCU Flash programming (V
A second power supply is implemented in the Industrial board, in order to provide the 12V
voltage supply required by the microcontroller during the In-Application Programming (IAP)
of the embedded Flash memory.
This power supply consists in a charge pump DC-DC regulator implemented by the ST
device ST662A, which is a step-up converter designed for the Flash memory programming.
Note that the charge pump converter is itself supplied by the switching regulator output V
The device can be shut down through line PD3 of the microcontroller, in order to reduce
power consumption and noise when IAP is not needed.
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Power supplies PCB area
DD
) stabilized on the output with an input range 5V ÷ 35V and it can be
DD
Figure 1, the N-MOS M1 is removed and the diode D9 is replaced
)
)
PP
UM0240
.
DD