Asking for the OP design recommendation

Hi Shh,

there are quite a lot:

https://www.ti.com/amplifier-circuit/op-amps/general-purpose/products.html#p1261max=5.5;16&p1261min=0.9;2.5&p1typ=0;0.01&sort=p1typ;desc

What speed do you need?

Kai

Hi SHH,

Take a look at our OPA2333P. The OPA2333P is available in a 2-mm × 2-mm 8-pin WSON package.

An open-drain output implies a comparator:
www.ti.com/amplifier-circuit/comparators/products.html#p358max=5.5;40&p358min=0.9;2.5&p1typ=0.000075;0.01

Again, what speed do you need?

The smallest comparators are TLV7011/TLV7031 in 0.8 mm × 0.8 mm 5-pin X2SON, or for dual comparators, TLV7012/TLV7032 in 2 mm × 2 mm 8-pin WSON.

Comparators with only one input and built-in voltage reference (e.g., TLV4051) have even smaller packages.