TLV61046A: TLV61046A is not working correctly for input voltage smaller than 4V

Ashwin Lele

Part Number: TLV61046A

I have built a boost converter circuit on a PCB using TLV61046A for converting LiPo battery's output of 3.7V to 24 V. I use the L,C,R values calculated by the official WEBENCH designer. I drive it using a constant voltage generator source for testing.

I get the expected 24V output for the input voltage above 4V but it drops to 15V when the input voltage drops below 4V. Additionally, there is a hysteresis present. If the input voltage starts at 4.5V and decreased, the output will stay at 24 until the input drops to 3.6V. It switches back to 24V after the voltage is increased to 4.1-4.2 V. I initially suspected of instability due to component values. However, if that were the case it should have been there for a fixed switching voltage instead of the observed hysteresis.

Can somebody please point out the reason behind this and how can it be corrected?

Thanks in advance!

over 4 years ago

0 Minqiu Xie over 4 years ago

TI__Mastermind 21565 points

Hi Ashwin：

Please share your schematic and waveform with me.

And is there any loading with your test? If yes, how about removing it?

0 Minqiu Xie over 4 years ago in reply to Minqiu Xie

TI__Mastermind 21565 points

Hi Ashwin:

As long time no hear from you, I assume you have solved the issue. If not, just reply below. Thank you!

And just let you know I'll out of office for more than one week. The reply will be delay. Thanks for your kind understanding.

0 Ashwin Lele over 4 years ago in reply to Minqiu Xie

Prodigy 50 points

Hi Minqiu,

Sorry for a late reply. I was trying to experiment with the loading conditions.

I am driving an OPAMP - LM 6211 (https://www.ti.com/lit/ds/symlink/lm6211.pdf?ts=1612936163455&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM6211 ) using the output of the boost converter. The 24V output of the boost converter acts as supply to this. The opamp is oscillating at frequency 'f'. When f is high (>500Hz) I see the corrupted output from the boost converter as shown in the picture. At lower frequencies, a constant 24V output is achieved. Is there a way to accommodate this loading in TLV61046A?