Hi Support team,
1. Why MCU “MSP430FR2155” & PSE “TPS23880RTQR” needs to have two DC to DC converter? may i combine to one, the reason behind is cost effective and space saving
2. for schematic, connect VPWR to pair 1/2 and 7/8. Please connect PSE_N5 to pair 3/6 and PSE_N6 to pair 4/5.
may i connected PSE_N5 to pair 3/6 and PSE_N6 to pair 7/8，it that workable?
3. what is the function for following circuit?
Hi Red,
Please see my comments below.
1. Why MCU “MSP430FR2155” & PSE “TPS23880RTQR” needs to have two DC to DC converter? may i combine to one, the reason behind is cost effective and space saving
[Penny]You don't have to have 2 DCDC converters for MCU and TPS23880 as long as you don't isolate the I2C signals between PSE device and MCU. I have seen 2 approaches: the digital isolater is placed between MCU and PSE; the digital isolator is placed between host CPU and MCU.
2. for schematic, connect VPWR to pair 1/2 and 7/8. Please connect PSE_N5 to pair 3/6 and PSE_N6 to pair 4/5.
may i connected PSE_N5 to pair 3/6 and PSE_N6 to pair 7/8，it that workable?
[Penny]If you want to design a IEEE802.3bt type 4 PSE, you will need to connect Vpwr to pair 3/6 and pair 4/5, PSE_N5 to pair1/2, PSE_N6 to pair 7/8. Please see the picture below.
3. what is the function for following circuit?
[Penny]It is better to consult with MSP430 team on this.
Why MSP430FR2155 is picked? Thanks.
Best regards,
Penny
