BQ25710: BG25710RSNG BOOST SWITCH ISSUE

Cooper Zhang1

Expert 2190 points

Part Number: BQ25710

Dear:

BQ25710 Operation condition：charge VIN =20V ，charge VOUT =15V （4cell battery）, enable in OAA mode ;

Issue :when adapt power supply, charge boost H/L side switch open frequency

Question ：

Isn't boost UG in open mode, when the charge works in buck mode （the input is 20Vin, the output is 15V）?Now I find that the H side gate on the Boost side firstly opens for a while and then turns off , like that switches frequently several times.

Would like to ask what is the reason?Are there any improvement measures?

the wave as below:

boost high side gate and low side gate:

charge vout=vsys=15V ,HG=boost H side gate

over 4 years ago

0 Angelo Zhang87 over 4 years ago

TI__Genius 11850 points

Hi Cooper,

Are you testing a BQ25710 EVM, or are you testing your own board? If you are using your own board, can you please send your schematic and try testing the BQ25710 EVM with the same test setup/conditions to see whether the behavior is different? I want to check the schematic to see whether any component values may be causing unstable operation.

In buck mode, Q1 and Q2 should be switching, Q3 should be off, and Q4 should be on. However, you observe that Q4 is also switching, correct? It would be helpful if we could see a waveform with SW1, SW2, VSYS, and the inductor current. This will show the converter's behavior more clearly.

Best regards,

Angelo

0 Angelo Zhang87 over 4 years ago in reply to Angelo Zhang87

TI__Genius 11850 points

Hi,

Since you have emailed me the schematic, I will close this E2E thread, and we can continue the discussion privately.

Best regards,

Angelo

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BQ25710: BG25710RSNG BOOST SWITCH ISSUE