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2020-5-22
UG2020-11 REF-Vacuum-C101-2ED User Guide
6.3
Auxiliary power supply
Figure 29 depicts the schematic of the auxiliary power supply for the REF-Vacuum-C101-2ED board. Two linear
LDO used for 12 V and 3.3 V power supply. U2 can be replaced by 5 V LDO or adjustable IFX1117ME V to achieve
higher power supply, for the application that needs higher SNR of motor current sample with external OPA.
Please note that the undervoltage level of 2ED2304S06F is 8.3~9.1 V, if the DC input is out of the 18 V~30 V
range; the output voltage of 78M12 needs to be double-checked to make sure 2ED2304S06F can respond to
PWM command correctly.
ZD2 &ZD3 are used to reduce power consumption on 78M12. For higher DC voltage input, higher-voltage Zener
diodes might be needed to make sure 78M12 will not over-heat. And for 12 V or 3S~4S Li battery applications,
please short ZD2 &ZD3, or bypass U1 directly.
Both 12 V and 3.3 V power supplies can output 100 mA to external circuit, with on-board cooling fan ON (default
configuration). If cooling fan is OFF or removed, the maximum output ability is in sum 100 mA, depending on
the temperature of ZD2 & ZD3 & U1.
Figure 29
Power supply section of the REF-Vacuum-C101-2ED reference design
6.4
Schematics for REF-Vacuum-C101-2ED
The overall schematic diagram for REF-Vacuum-C101-2ED is provided in Figure 30.