User Manual

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Revision 1.4

2019-10-11

EVAL-M3-CM615PN User Manual

iMOTION™ Modular Application Design Kit

Hardware description of EVAL-M3-CM615PN

5.1.2

Hardware Modification for AC Voltage sensing to work with IRMCF188

As mentioned in the previous setion, AC voltage sensing is in the front of rectifier bridge U1 by default for this

power board EVAL-M3-CM615PN as shown in Figure 10. But for control board EVAL-M3-188 with controller IC

IRMCF188, AC Voltage sensing should be behind the rectifier bridge U1. To work with control board EVAL-M3-

188 or IRMCF188, power board EVAL-M3-CM615PN should be modified by assembling 1MΩ AC Voltage sensing

resistors R4 and R14 and removing the resistors R1 and R10.

5.1.3

PFC External Current feedback configuration and calculation

The PFC shunt resistor RS1 is 30mΩ for EVAL-M3-CM615PN. But for control board EVAL-M3-102T, the current

input value is product of the shunt resistance in milliohms and gain of External current sense amplifier as

shown in Figure 14.

Figure 14 PFC Current shunt feedback and sample timing

Figure 15 depicts IPFC- current feedback sensing circuity on EVAL-M3-102T evaluation board. Please note that

the default external amplification gain is less than 1 for current sense in this evaluation board.

Figure 15 The PFC Current feedback circuit for EVAL-M3-102T evaluation board

Based on the principle of Kirchhoff's voltage law,

= + =1213

R7

1Kohm 1/10W 1%

R6

12Kohm 1/10W 1%

C15

220pF 10V

3.3V

IPFC-

R25

1Kohm 1/10W 1%

IPFC0

iMOTION

Controller

12

Rsh

Ish

Current shunt resistor

on power board

V3

V4

IPFC-

IPFC