UM1036 datasheet(14/47 Pages) STMICROELECTRONICS

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Board description

UM1036

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DocID18293 Rev 2

2.3

Circuit description

2.3.1

Power supply

The power supply for the STEVAL-IHM028V2 evaluation board is implemented as

a wide range converter. The range of the input voltage is from 90 VAC or 125 VDC up to 285

VAC or 400 VDC. This range allows the evaluation board to be used in direct connection

with various single phases as well as the PFC input stage.

If the input AC voltage does not surpass 145 VAC, it is possible to apply the input voltage

doubler, this is done by shorting the W15 jumper. This configuration almost doubles the

input AC voltage to a standard level and allows to evaluate the motor control application with

a low level of input AC voltage.

The auxiliary power supply for all active components on the evaluation board is

implemented as a buck converter based on U2 VIPer26L which works with a fixed frequency

of 60 kHz. The output voltage of the converter is +15 VDC. Voltage is fed into the intelligent

power module (IPM) as supply voltage, as well as into linear regulators LF33ABDT and

L78M05AB. Linear regulators provide +3.3 VDC and +5 VDC for supplying operational

amplifiers and further related parts placed on the evaluation board. The selection of supply

voltage for hardware peripherals placed on the board is done with jumper W1. In the “A”

position the supply voltage selected is +3.3 V and in the “B” position it is +5 V. Thanks to

jumper W3, it is possible to supply the connected MCU driving board with related supply

voltage. Maximal consumptive current of the MCU unit must not surpass 50 mA. Please

refer to the VIPer26LD datasheet for more information.

Information regarding the value of the supply bus voltage on the main filtering capacitors is

sensed with the voltage divider built around R2, R5, and R8 and is fed into the dedicated

control unit through the J2 connector. The proper voltage partitioning for applied resistor

values is 0.0075.

The presence of +15 VDC on the board is indicated with the D5 green LED “Power ON”.

Figure 9 describes the power supply section with a simplified block diagram.

Figure 9. Power supply block diagram

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