IRMCS3043

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2.5

PFC IGBT and Diode

At the PFC frond-end, one piece of IRGP4063DPbF trench IGBT and one piece of 30ETH06 hyperfast diode are

mounted on the same heat sink under the board. A 15-mΩ shunt resistor is in series with the inductor current flowing

path at the negative DC bus side. The shunt provides PFC current feedback as well as over-current protection (OCP).

The voltage across the shunts is fed to a comparator circuit. The comparator initiates the over-current shutdown

(PGatekill), and the PGatekill signal is fed to IRMCF343 IC. The OCP is about 20A peak. For more information

regarding trench IGBTs and hyperfast diode, please refer to their datasheets.

2.6

PFC Inductor

One piece of PFC inductor is provided separately from the PCB, and should be connected to the J2 connector. The

inductor shown in Figure 2 is 1.5mH at 15A Idc, with 10Arms current rating. You can use your own inductor for the

evaluation and test. The choice of inductor involves trade-offs in PFC control performance (current ripple, harmonics

and power factor), switching frequency, cost, space, power loss and EMI noise. The PFC switching frequency for the

IRMCS3043 is 30kHz, and the typical recommended reasonable inductance range is about 1mH to 1.5mH.

2.7

IRAM

At the inverter side, one piece of IRAMX16UP60A-2 is mounted on the same heat sink under the board. There are

two 20-mΩ shunt resistors (in parallel) that are inserted into the negative DC bus and external to the IRAM. These

shunts provide motor current feedback as well as over-current protection. The voltage across the shunts is fed to a

comparator circuit. The comparator initiates the over-current shutdown (CGatekill), and the CGatekill signal is fed to

both the IRAM and IRMCF343 IC. With the 10-mΩ shunt resistance and threshold set up of the comparator, the

OCP current is about 20A peak. For more information regarding IRAM, please refer to IRAM datasheet.

2.8

Power Supply

The switched-mode power supply (SMPS) operates at about 80 KHz and generates 15V(VCC), 5V and 3.3V. A 1.8V

DC voltage is generated from 3.3V by a linear regulator IRU1208. All these voltages are biased to the negative DC

bus. In addition, this SMPS also generates an isolated 12V which is used for the RS232 communication.

2.9

EMI Filter

The passive EMI filter on the board consists of two 1-µF X-caps, two 4.7-nF Y-caps and a 4-mH common-mode

inductor.

2.10 DC Bus Capacitors