UM1483

Board description

Doc ID 022398 Rev 1

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3.3

Board architecture description

3.3.1

Power supply

The power supply in the STEVAL-IHM036V1 demonstration board is designed for European

supply voltage range 230 VAC. The real range of the input voltage is from 195 VAC or

275 VDC to 265 VAC or 375 VDC.

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

implemented as a buck converter based on U1 VIPer16LD 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 regulator

L78L33ACU. The linear regulator provides +3.3 VDC for supplying MCU, operational

amplifiers, and further related parts placed on the demonstration board. Please refer to

STMicroelectronics VIPer16LD datasheet for more information.

For testing purposes the board may also operate in wide supply voltage range from

18 VDC to 400 VDC. A dual supplying mode could be used in this situation. The jumper

SW4 must be disconnected. In this mode, voltage on the input connector J1 is normally

linked through power switches to the motor. An external auxiliary voltage is fed through the

J5 connector from an external power source. The voltage of the used external power supply

must be in the range +14.8 V to +15.5 V with availability to sink current 0.5 A. This is a mode

which allows to use the demonstration board for various supply voltages. It is especially

convenient for low voltage motors.

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

sensed with the voltage divider built around R1, R2 and R3 and is fed into the MCU to ADC.

The proper voltage multiplication for applied resistors divider is 116.

The presence of +15 VDC on the board is indicated with D9 green LED “Power ON”.

Figure 6 describes the power supply section through a simplified block diagram.

Figure 6.

Power supply block diagram