Circuit and method for generating reference voltage and reference current

A circuit for generating reference voltage and reference current, comprising:

• a band-gap reference circuit, configured to generate a first current with a positive temperature coefficient flowing through a first node of the bank-gap reference circuit, thereby generating a temperature-independent reference voltage to be outputted at the first node;
• and
• a voltage-to-current converting circuit, coupled to a second node of the band-gap reference circuit and configured to convert a voltage with a negative temperature coefficient at the second node into a second current with a negative temperature coefficient flowing through the first node;
• wherein the band-gap reference circuit and the voltage-to-current converting circuit share a common current source coupled to the first node for outputting a reference current;
• wherein the reference current is divided into the first current of the band-gap reference circuit and the second current of the voltage-to-current converting circuit at the first node, having a temperature coefficient substantially equal to zero by combining the first current and the second current.

A circuit for generating reference voltage and reference current, comprising:

• a band-gap reference circuit, for outputting a temperature-independent reference voltage, the band-gap reference circuit comprising:
• a proportional-to-absolute-temperature (PTAT) current generating part, comprising:
• a first junction transistor and a second junction transistor coupled to each other;
• and
• a first resistor device, a second resistor device and a third resistor device, respectively coupled between the second junction transistor and the second resistor device, between the first resistor device and a first node, and between the first junction transistor and the first node;
• and
• a first operational amplifier, having a first input terminal coupled between the first resistor device and the second resistor device, a second input terminal coupled between the third resistor device and the first junction transistor, and an output terminal;
• and
• a voltage-to-current converting circuit, comprising:
• a second operational amplifier, having a first input terminal coupled between the first junction transistor and the third resistor device, a second input terminal and an output terminal;
• and
• a bias current source, comprising a bias transistor, the bias transistor having a first terminal coupled to the output terminal of the second operational amplifier, a second terminal coupled to the first node and a third terminal;
• and
• a fourth resistor device, having one end coupled to the third terminal of the bias transistor and the second input terminal of the second operational amplifier;
• wherein the band-gap reference circuit and the voltage-to-current converting circuit share a common current source, the common current source comprising a feedback transistor coupled to a voltage source, the first node and the output terminal of the first operational amplifier for outputting a temperature-independent reference current.

A method for generating reference voltage and reference current, comprising:

• generating a temperature-independent reference voltage by generating a first current with a positive temperature coefficient, and simultaneously generating a feedback bias voltage and a voltage with a negative temperature coefficient;
• converting the voltage with a negative temperature coefficient into a second current with a negative temperature coefficient;
• and
• generating a reference current based on the feedback bias voltage, wherein the reference current is a combination current of the first current and the second current to have a temperature coefficient substantially equal to zero.