TI中文支持网Part Number:TPS61289
Hello! Question 1: This specification document does not mention the gate driver driving capability and time of the TPS61289 transistor. I need to know its gate drive internal resistance and driving current in order to make a selection. Question 2: The rated current of this chip is 20A. If the current-limiting resistor is 10K, will it still trigger the 20A overcurrent protection? Question 3: Can the chip's VCC be externally powered and does supplying 6.5V to it have any impact on the internal components? Thank you
Taylor：
Hi,
We have received your post and the investigation will take some time. Thank you for your patience.
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Vivian Gao：
1.The driver circuit is not a mere internal resistance. We recommend Qgd<5nC to ensure switching speed. Please share several alternative solution and I can comment on the selection.
2.No, if Ilim is set to 10k, the IC current limit function will not work normally. This is out of our current limit range and we do not recommend this.
3.No, external VCC is not supported by TPS61289.
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MOU YE：
Thank you for your reply. My usage scenario is that the tps61289 operates in boost mode, with an input of 3V and an output of 17V at a current of 5A. In this extreme case, the peak current of the built-in current-limiting MOSFET in the chip will exceed 28A, but the average current is relatively low. How should I set the current-limiting resistor? The average input current exceeds 28A. How should I choose a MOSFET?
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Vivian Gao：
The TPS61289 will not be able to support your application. The max current limit is only 20A and cannot be changed
