Rail splitting virtual ground generator for single supply systems

A method for creating a virtual ground reference voltage for use in a single supply system, comprising the steps of:

• providing a pair of precision resistors coupled between a first and second voltage supply;
• providing a temperature stable bias current source coupled to said first voltage supply;
• providing an operational amplifier having increased current drive capability, powered by said bias current source and said second voltage supply;
• coupling a predetermined reference voltage produced by the said pair of precision resistors one input terminal of said operational amplifier;
• coupling the output of said operational amplifier to a voltage output terminal, and further coupling said voltage output terminal to a second input terminal of said operation amplifier;
• and
• operating said operational amplifier in a unity gain configuration so as to provide a voltage at the voltage output terminal that is one half the difference in said first and second supply voltages.

An integrated circuit implementing a virtual ground reference voltage circuit, comprising:

• first and second voltage supply terminals;
• a voltage output terminal;
• first and second resistors, coupled to an voltage reference node and further coupled between said first and second supply voltages, operable such that a predetermined reference voltage is available at the voltage reference node;
• a bias current source coupled to said first supply voltage;
• an operational amplifier coupled to said reference voltage in a unity gain configuration, having an output coupled to said output terminal, and powered by said bias current source and said second supply voltage;
• a noise reduction input coupled to said reference voltage;
• and
• operable to provide a stable voltage at the output terminal which is equal to half the difference between said first and second supply voltages over a wide range of supply voltage and temperature conditions.

A rail splitting virtual ground generator circuit, comprising:

• a resistor voltage divider coupled between first and second supply voltages operable to provide a predetermined reference voltage;
• a bias current source coupled to said first supply voltage;
• an amplifier coupled to said reference voltage and having an output coupled to an output terminal, said amplifier being powered by said bias current source;
• and
• operable to provide a stable voltage at the output terminal which is equal to half the difference of said first and second supply voltages.

A method for creating a rail splitting virtual ground generator circuit, comprising the steps of:

• providing a resistor voltage divider coupled between first and second supply voltages operable to provide a reference voltage;
• providing a bias current source coupled to said first supply voltage;
• providing an amplifier coupled to said reference voltage and having an output coupled to an output terminal, said amplifier being powered by said bias current source;
• and
• operating said amplifier and bias current source to provide a stable voltage at the output terminal which is equal to half the difference of said first and second supply voltages.