Hi,
Quote:If I have a resistive ladder ( in DAC for instance) and this ladder is connected to a Vref voltage. Because the ladder itself consumes a large curent, Vref should be connected the output of a regulator (rather than the output of a reference circuit) so that Vref is not varied with the current variations in that resistive ladder. Am I right ?
I don't think this is correct. A resistive ladder is a more or less constant load. You don't need a voltage regulator here. You need a voltage reference with maybe a unity gain buffer. BTW a voltage regulator usually has an extremely large off-chip inductor while a bandgap can be implemented entirely on-chip.
I believe you would need voltage regulators to separate power domains. For example, although a system may have only 1 power supply such as a battery, it may include several chips operating at different voltage levels. Furthermore, their power consumptions may vary in time depending on the functions they are performing. Voltage regulators are required to ensure that the power domains don't interact with each other, and the supply voltages are stable despite changes in loading conditions.
Quote:Is the output voltage of a typical regulator independent of process and temperature variations like references?
It is not as stable as a voltage reference (due to the changing loading conditions), and doesn't need to be as precise either. A voltage reference should be very precise.
cheers,
Aaron