Tool/software:
Hi!
I assembled a circuit of a priority power controller from 4 channels TPS259470ARPW. The outputs of all channels are connected together and feed a pulse power supply with a load of 9 Ohms and a capacitor of 470 μF.
The time when one channel is turned off and the next one is turned on is 200 μs. It is necessary to reduce this time. At the terminals of ITIMER and DVDT, I changed the capacitors from open to 10 μF. It did not help.
How can I adjust the channel switching time?
Hi Rakesh!
Thanks for the answer. DVDT was also open, did not help. I did not notice an increase in the channel switching speed.
The voltage of the upper channel VUSB = 5V (from the USB connector). Voltages VIN1-VIN3 = 3.0...8.4V, from lithium batteries.
The higher the channel, the higher its priority.
There is another very significant problem. When the voltage of the priority channel VIN is smoothly reduced to the shutdown threshold, when the next channel in priority is already turned on, these channels begin to switch between each other. And the voltage of the second channel is transferred to the input of the first. The signal on UVLO at this moment crosses the on and off thresholds. And this does not stop.
How to get rid of this effect?
Hi Ben,
The turn-on delay of eFuses is in the order of 100's of us. These devices are intentionally designed for slow turn-on as main purpose/functionality is to limit the inrush. Please consider increasing Cout to buffer the load for this interval.
To trigger reverse current protection (RCP), certain reverse current has to flow through the device to establish reverse voltage 16.9mV. otherwise, the device does not trigger reverse current protection. It is a challenge to establish reverse current for slow changing signals.
One way to address the problem is by increasing the input capacitance at the eFuse input which could draw higher reverse current to help trigger RCP.
Best Regards,
Rakesh
