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because I want to have PWM dimming LED, I have connected PWM signal to EN pin of TPS63060. I wonder is this correct? According to datasheet chip have soft-start so it shouldn't destroy LED. PWM signal have 180Hz frequency, LED is white 1W power.

Schema: enter image description here

Simulation: enter image description here Green signal is output voltage, blue LED current and red one is EN signal. At start we can see one peak for around 330mA and after that signal is stabilizes to 300mA.

TPS63060 Datasheet

athosikish
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  • Show the complete circuit proposal and include data sheet links for the chip and the LEDs. – Andy aka Nov 23 '20 at 09:56
  • This is circuit in LTspice : https://imgur.com/a/8JdX6px This is datasheet: https://www.ti.com/lit/ds/symlink/tps63060.pdf?ts=1606046278019&ref_url=https%253A%252F%252Fwww.google.com%252F LED is white 1W and PWM signal for EN pin have 180Hz. – athosikish Nov 23 '20 at 10:06
  • You can embed schematics into your question. Given that it is an LTSpice schematic, what does running a simulation tell you about LED current? – Andy aka Nov 23 '20 at 10:10
  • https://imgur.com/a/6gPduRN Green signal is output voltage, blue LED current and red one is EN signal. At start we can see one peak for around 330mA and after that signal is stabilizes to 300mA. – athosikish Nov 23 '20 at 10:14
  • You need to embed all of this information inside your question above. This isn't a forum, it's a Q and A site and people expect full details inside the question. – Andy aka Nov 23 '20 at 10:23
  • Already change it. – athosikish Nov 23 '20 at 10:28
  • Images can be directly embedded - nobody wants to follow links when images can be directly displayed. All the relevant technical details in comments should be in the body of the question. I thought I was clear about that? – Andy aka Nov 23 '20 at 10:31
  • I corrected it, thanks for helpful comments – athosikish Nov 23 '20 at 10:39
  • The minimum level of soft start current is 400 mA so if you are expecting this to have an effect then it won't because you are running your LED at 330 mA (i.e. below the SS current limit). I also see a discrepancy in the current produced; if you have a 1.66 ohm current sense resistor, the peak current to the LED should be no more than 300 mA and not 330 mA. – Andy aka Nov 23 '20 at 10:53
  • So maybe I should use this one to control LED ? https://www.onsemi.com/pub/Collateral/NCP5030-D.PDF It looks similar to the TPS63060 but producent describes EN/CTRL as pin which can handle PWM. – athosikish Nov 23 '20 at 11:05

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