LM5177EVM-HP: LM5177EVM-HP

Thanks for reply.

1) How to enable FPWM mode in LM5177EVM evaluation board ?

2) After enabling FPWM mode can i use any port as input or output ?

3) How to enable for CC mode ?

4) After enabling FPWM mode, can input perform buck-boost respective operation to maintain output voltage and vice versa ?

5) Can i get external circuit for limiting charging voltage ?

Regards

Hi Sachin,

1. set the MODE jumper to VCC = FPWM

2. Note: Vin needs to be above VDet level to enable the device 

bidirectional mode means it works in both directions - so what is input and what is output

3. see datasheet: 7.3.13 Current Monitoring and Current Limit Control Loop

4. not sure if i understood this question

5. see:

Best regards,

 Stefan

Hi Stefan,

As per suggestion, VCC and MODE pin shorted using jumper at JP1. But still EVM not operating in bi-directional mode.

Let know if any other changes required in EVM to operate in bi-directional mode ?

Thanks

Hi Sachin,

please let me know the details of your setup and behavour you would expect to see.

Best regards, 

Stefan

Hi Stefan,

The requirement is bi-directional DC to DC converter.

So need EVM to work in bi-directional, where any port can perform either sourcing or sinking mode.

Thanks

Hi Sachin,

sorry, may have not phrased properly: When you try the backup operation, how does your setup look like:

- what have you set or changed on the EVM

- what voltage did you connect on which pins 

- any load connected ?

- what do you measure

- and what do you expect but not measure

Best regards, 

Stefan

Hi Stefan,

Please find below reply,

- As suggested, i checked jumper JP1 for VCC and MODE pin connection it was already connected.

- Connected power supply at J1 and J3 supplying voltage upto 28Vdc. Observed 16Vdc at J2 and J4.

-At present no load was connected.

- At present measured voltages.

- For verifying bi-directional mode. I changed power supply terminal to J2 and J4 feeding max. 12Vdc but there was no voltage observed at J1 and J3.

Thanks

Hi Sachin,

the LM5177 requires a voltage on VIN to start operation (see datasheet VDET)

When working with a battery this is typically available, when trying to charge a capacitor some startup circuit would be required.

Note: the LM51772 can disable this option.

Best regards,

 Stefan

Hi Stefan,

I will try by keeping Vdet voltage values.

Thanks,

Sachin