Although buffers and drivers don?t appear to add functionality to a circuit, these apparently simple interface elements are essential to viable circuit design and operation.
The design assignment is clear: build a small datalogger which will be inaccessible once in place, yet must operate for a minimum of 20 years.
Voltage drop and low voltage at the load is more than just a nuisance. It can cause circuits to not function at all, or function erratically when the voltage is at the edge of the IC specification.
Be sure your system is protected against power-supply faults as well as the complementary scenario.
Sensing of current magnitude is critical in many applications and often done by measuring the voltage across a shunt resistor, but even this simple technique has subtleties and issues to resolve.