2.048V shunt reference — the ADC bias anchor
The Texas Instruments LM4040CIM7-2.0/NOPB is a precision shunt voltage reference with a fixed 2.048V output and ±0.5% initial tolerance. It is designed for applications requiring a stable voltage reference — ADC reference, comparator threshold, or precision bias — in a tiny SC-70-5 footprint.
No official replacement or successor is listed on the TI lifecycle record.
SC-70-5 footprint — board-space constraint
The SC-70-5 (SOT-353) package measures approximately 2.0mm x 2.1mm with 0.65mm pin pitch. This is the smallest footprint for a precision shunt reference — the part was likely chosen to fit a tight layout. Any replacement must match this land pattern.
15 mA output current — load budget check
The LM4040CIM7-2.0/NOPB can source up to 15 mA and requires a minimum cathode current of 65 µA to maintain regulation. The shunt topology means the total current drawn from the supply is the load current plus the cathode current — budget the series resistor accordingly.