Board architecture

UM0580

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7

Board architecture

The STEVAL-IHM021V1 can be schematized as shown in Figure 5.

7.1

Power supply

The power supply can address the AC input voltage ranging from 30 Vac up to 270 Vac. The

alternate current input is rectified by a diode bridge and a bulk capacitor to generate a direct

current bus voltage approximately equal to

√2 Vac (neglecting the voltage drop across the

diodes and the bus voltage ripple). A VIPer12AS-E is then used in a buck converter

configuration to generate the +15-V supply voltage of the gate drivers. Finally, a linear

regulator (L78L33ABUTR) is used to generate the 3.3 V used to pull up the low side gate

driver inputs so as to prevent the undesired turn-on of low side switches when the J5

connector is unplugged.

Figure 6 shows a block diagram of the power supply.

Figure 5.

STEVAL-IHM021V1 block diagram

AM01261v1

Figure 6.

Power supply block diagram

AM01262v1