Seeking low-power chip 3.3V DC DC buck

[Maydori]

Hello,
This is my first topic.Very glad that I could gain help from all of you.
Input is 4.2V lithium batteries, need 3.3v output power to the CPU, so it is necessary to support low-power lithium battery and input. 1117 itself is relatively large power consumption, TLV70033 specified minimum output current is 200ma, lithium batteries do not operate reliably input, Is there other chip can be useful?
Regards,
Maydori

[Phoenix]

Welcome.

What's the current draw of the device you're hoping to power (microcontroller?)? TLV70033 specified MAX output current is guaranteed to be not LESS than 220mA (when Vout is 0.9xVnom), typical rating of 350mA, maximum of 550mA, drawing anything below that 220mA will be fine so long as other datasheet conditions are met (regulation is guaranteed down to 10mA minimum load current).

What exactly are you trying to do?