Other Parts Discussed in Thread: TPS55340
Hi ,
I am currently using TPS55340 in one of my design. Following the specifications. When I am operating IC at low input voltage of 3.6V, I observe input voltage shape change as in below image; Low level voltage is going as low as 2.480V , well below UVLO limt of IC. But there is no dip on o/p voltage of 24V. Why this is happening ?Another observation is , if we increase input capacitor to reduce this ripple, still voltage stabilize at 2.5V only. Whether IC's UVLO circuit is playing any role here. Also, If UVLO is 2.5V, Why IC is not stopped working ? Now when input voltage is falling as low as 2.5V which is well below ICs input voltage range, whether this observation will If we cause reliability issue for IC ?
If we give external table top Dc supply as input voltage and reduce it to 2.9V, it dips to 2.5V and remain there unless it is again increasing above 3V. Does this observation is because of UVLO pin internal structure circuit ? How really it is controlling this ?
Vin = 4V to 15V
Vout = 24V, 0.1A
Thanks in advance
Prafulla S.