SOT-23 is used to simplify the process.The voltage reference should have 0.1% tolerance.A voltage reference ic with 6 pins is settled.Voltage 3.3V is outputted.
LT6656BIS6-3.3#PBF Features
0.1% Tolerance
LT6656BIS6-3.3#PBF Applications
There are a lot of Analog Devices, Inc. LT6656BIS6-3.3#PBF Voltage Reference applications.