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TPS61193-Q1: fault will not be triggered when SW pin exceeds max current
Part Number: TPS61193-Q1 Dear expert: It’s found that fault will not be triggered when SW pin exceeds max current. Since application condition where the 2A limit is exceeded continuously is not allowed, does tps61193 has any mechanism to protect against this case? BTW, how to understand OCP described in “extensive fault detection feature”?
Hi Lin, I have following questions according to your description. How long does your current of SW exceeds 2A last? Can you provide any waveforms?
Hi Charles To separate UVLO and OCP, my Vin is supplied by 12V, and DCDC inductor is supplied by 4V, respectively. When this 4V is decreased slowly to 2.5V, no fault is triggered. This illustrates that pin SW over current will not trigger fault. Moreover, Vin is supplied by 4V, and DCDC inductor is supplied by 12V, respectively. When this 4V is decreased to 3.95V, fault is triggered immediately. This illustrates that pin UVLO will trigger fault. So there’s no need to provide waveform. Looking forward for your reply and thanks!
Hi Lin, BTW, how to understand OCP described in “extensive fault detection feature”? When the transient SW DC current exceeds 2A, it will lasts for 1.5s and then the current limit is automatically increased to 2.5 A for a short period of 1.5s. And then this total 3s periods repeats until thermal shutdown. To ensure the SW DC current exceeds 2A, please also provide your load current and the value of inductor when the input voltage is decreased slowly to 2.5V. I suggest that you measure the current actually. Please also note that the table 3, the SW DC current OCP is not included in the fault detection. However, if the SW DC current OCP happens, the behavior of chip is described in my first reply to your question. You can check this by measure the inductor current through current probe. Hope this helps.
Hi charles Thanks a lot! Surely SW current decreases and backlight darkened as VIN decreased to 2.5V, as you said. OCP is not triggered because no thermal down happened in my application.
Hi Lin, Great! Please click the "resolved" and I will close this thread.