Low noise reference voltage generator and load regulator

An apparatus comprising:

• a buffer circuit configured to transfer a signal from an input node to an output reference node using a power supply voltage on a first power supply node;
• a current mirror coupled to the output reference node and configured to generate a mirrored current through a first node based on a first current through a second node and a voltage on the output reference node;
• a resistor coupled between the second node and a second power supply node;
• a first transistor of a first type coupled between the first node, the second node, and the second power supply node, the first transistor having a gate terminal coupled to the second node, a drain terminal coupled to the first node, and a source terminal coupled to the second power supply node, the first transistor being configured to develop a voltage drop across terminals of the resistor to generate the first current, the voltage drop being equal to a gate-to-source voltage across the gate terminal and the source terminal;
• and
• a level-shifting circuit configured to level shift a voltage on the first node to drive the input node of the buffer circuit.

An apparatus comprising:

• means for generating a current flowing between an output reference node and a first power supply node based on a voltage drop across a resistor, the voltage drop being equal to a gate-to-source voltage across a gate terminal of a transistor and a source terminal of the transistor;
• means for mirroring the current to generate a mirrored current flowing between the output reference node and a drain terminal of the transistor;
• means for level-shifting a voltage on the drain terminal of the transistor to generate a level-shifted voltage;
• and
• means for buffering the level-shifted voltage using a voltage on a second power supply node to generate a reference voltage on the output reference node.