Apparatus and method for high voltage bandgap type reference circuit with flexible output setting
AssigneeApple Inc.
InventorsTurev Acar, Selcuk Talay, Burak Dundar
Life of this patent
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Abstract
An apparatus and method for a voltage reference circuit with flexible and adjustable voltage settings. A voltage reference circuit, comprising a PTAT Current Generator configured to provide current through a first resistor, a CTAT Current Generator configured to provide a CTAT current through a second resistor, a PTAT-CTAT Adder circuit configured to sum the PTAT current, and the CTAT current, wherein said sum of the PTAT and CTAT current through a third resistor is configured to provide an output voltage greater than a silicon bandgap voltage.
Claims16
A high voltage reference circuit configured to operate with a supply voltage up to 24 Volts, comprising:
- a proportional to absolute temperature (PTAT) Current Generator configured to provide a PTAT current through a first resistor;
- a complementary to absolute temperature (CTAT) Current Generator comprising a capacitor for compensation, configured to provide a CTAT current through a second resistor, wherein a first current mirror connection is established between the CTAT Current Generator, the PTAT Current Generator and a PTAT-CTAT Adder circuit, wherein the PTAT-CTAT Adder circuit is configured to sum said PTAT current and said CTAT current;
- a second current mirror connection is established between the CTAT Current Generator, the PTAT Current Generator and the PTAT-CTAT adder circuit, wherein the second current mirror connection comprises a plurality of transistors, and all the transistors of the second current mirror connection are high voltage p-channel (HP) transistors and the capacitor for compensation is connected to a HP transistor of the second current mirror connection in the CTAT Current generator and to a first terminal of the second resistor;
- wherein said sum of said currents generated by said PTAT Current Generator and said CTAT Current Generator flowing through a third resistor is configured to provide an output voltage greater than a silicon bandgap voltage and wherein the current generated by the PTAT Current Generator and the current generated by the CTAT Current Generator are separately generated so as to be separately adjusted as desired.
A method for providing a reference voltage by a high voltage reference circuit, comprising the steps of:
- providing a proportional to absolute temperature (PTAT) current through a first resistor by a proportional to absolute temperature (PTAT) Current Generator;
- providing a complementary to absolute temperature (CTAT) current through a second resistor by a complementary to absolute temperature (CTAT) current generator comprising a capacitor for compensation, wherein a first current mirror connection is established between the PTAT Current Generator, the CTAT Current Generator and an PTAT-CTAT adder circuit;
- providing a second current mirror connection established between the CTAT Current Generator, the PTAT Current Generator and the PTAT-CTAT adder circuit, wherein the second current mirror connection comprises a plurality of transistors, and all the transistors of the second current mirror connection are high voltage p-channel (HP) transistors and the capacitor for compensation is connected to a HP transistor of the second current mirror connection in the CTAT Current generator and to a first terminal of the second resistor;
- summing said PTAT and said CTAT currents to create a summed PTAT/CTAT current;
- providing an output voltage greater than a silicon bandgap voltage by passing said summed PTAT/CTAT current through a third resistor;
- and
- further providing a startup circuit configured to provide a signal to said PTAT Current Generator.
Dependencies are inferred from the claim text.