L7987LTR only provides 0.5 A max current rather than 2 A.

[alexjafari2005]

Posted on November 05, 2016 at 19:04

Hi

I would like to use L7987LTR in a few designs. The datasheet of the IC says its able to provide 2 A current however I can only measure 0.5 A. I have tested the schematics in 3 different layouts and layouts all seem to be good but all have the same behaviour. This makes me believe the problem is not in layout.

Moreover, I have tried a few differnet inductors (10uH) and diodes but I only measure 0.5 A output current. What am doing wrong? why does not the IC provide more current?

Thank you for you time in advance.

L2 = NR8040T100M (3.1A 2 mOhm Max ), LQH43PN100M26L, 744045100

D5 = NRVTS260ESFT1G (650mV @ 2A), B340B-13-F (500mV @ 3A)

Best regards,

-Alex

#dc-dc-conversion #l7987

[alexjafari2005]

Posted on November 13, 2016 at 09:19 Hi, Please find my schematics and layout attached. Best regards, ________________ Attachments : L7987LTR_Support_request.png : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Htzt&d=%2Fa%2F0X0000000abB%2FiEtEZeLuRd5J8Y.2PtgTjVkLWdjGFBBDk2aPELyiUck&asPdf=falseL7987LTR_Support_request_layout.png : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Htzy&d=%2Fa%2F0X0000000abC%2F7QhtrL_LTsHGEfp.6iPOw7SWTOwQ6TZDODt_rJ0ZDmY&asPdf=false

[AMens.1]

Change R34 to 39K.

edit: oeps...just saw it's a very old post :see_no_evil_monkey: