IRMCS3041

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2.3 IRMCF341

2.3.1 Power

IRMCF341 requires 3.3V and 1.8V. VDD1 is 3.3V used for I/O and VDD2 is 1.8V for digital logic. AVDD is 1.8V

for analog and PLLVDD is1.8V for PLL. Only one source of 1.8V is shared in IRMCS3041 system. Typical current

value for 1.8V is less than 100mA.

2.3.2 Crystal

A 4 MHz crystal is used to generate the system clock. Actual system frequency is adjustable by changing Phase

Locked Loop configuration through Special Function Registers. For more information regarding the clock, please refer

to the IRMCx300 Reference Manual.

2.3.3 Reset Circuit

IRMCF341 doesn’t require external RC circuit for reset. The reset switch can be used to initialize the JTAG debugger.

For more information regarding reset, please refer to the IRMCx300 Reference Manual.

2.3.4 EEPROM

Boot load takes place at power-up to load 8051 code and MCE code from an external EEPROM to internal RAM of

IRMCF341. EEPROM can be written by MCEDesigner.

2.3.5 Digital I/O

Only some of the digital I/O’s are used in IRMCS3041. For example, ‘P1.5’ and ‘P1.6’ are used to drive the LED to

indicate the status of the system. The remainders are connected to headers (J3, J7) for the user’s convenience.

2.3.6 Analog Input

Analog channels are connected to header J5 for ease of use.

2.3.7 Single Shunt Current Feedback

IRMCF341 contains an Operational Amplifier for single shunt current reconstruction circuit. Resistors and capacitors

for amplifier circuit are placed very close to the pins. Note that there is a separate trace from shunt resistor instead of

sharing a plane with negative DC bus ground to get better current feedback.

2.4 IRAM

IRAMS10UP60B in mounted on a heat sink under the board. Voltage across 33.3 mΩ shunt is fed to ‘Itrip’ pin of

IR21363 high voltage gate driver IC through low pass filter with 2 μsec time constant to initiate the over-current

shutdown (Gatekill). For more information regarding IRAM, please refer to IRAM datasheet.

2.5 Power Supply

Switch mode power supply operates at about 80 kHz and generates 15V(VCC), 3.3V and isolated 5V. 1.8V is

generated from 3.3V by a linear regulator IRU1208.

2.6 EMI Filter

Passive EMI filter on the board consists of two 0.1 μF X-caps and two 2.2 nF Y-caps and a 1 mH common mode

inductor. Y-caps are connected to the heat sink through a metal bar and to J1 pin 1, which is assigned as earth ground.

2.7 DC Bus Capacitor

have a dynamic braking unit. In case of field weakening operation, it is recommended to use an external regenerative

unit or a braking unit for safety. Pin 4(GND) and Pin 5(DCP) of J1 can be used for connecting an external unit.