Self-biased operational transconductance amplifier-based reference circuit
AssigneeXilinx, Inc.
InventorsIonut C. Cical, John K. Jennings, Diarmuid Collins
Life of this patent
Estimating the term…
Abstract
A device may include a voltage-to-current converter circuit having an operational transconductance amplifier (OTA), the voltage-to-current converter circuit for generating a bias current that is proportional to a reference voltage at a reference voltage input port of the OTA, and a bias current feedback path for providing the bias current to a bias current input port of the OTA. The device may further include a startup current generator circuit coupled to the bias current input port of the OTA, the startup current generator circuit controllable to provide a startup current to the bias current input port during a startup of the device and to be deactivated after the startup of the device.
Claims20
A device, comprising:
- a voltage-to-current converter circuit, the voltage-to-current converter circuit comprising an operational transconductance amplifier (OTA), the voltage-to-current converter circuit for generating a bias current that is proportional to a reference voltage at a reference voltage input port of the OTA;
- a bias current feedback path for providing the bias current to a bias current input port of the OTA;
- and
- a startup current generator circuit, the startup current generator circuit coupled to the bias current input port of the OTA, wherein the startup current generator circuit is controllable to provide a startup current to the bias current input port during a startup of the device and is controllable to be deactivated after the startup of the device.
A device, comprising:
- an operational transconductance amplifier (OTA), comprising:
- a reference voltage input port;
- a feedback voltage input port;
- a bias current input port;
- and
- an output voltage port;
- a first p-channel metal-oxide-semiconductor field effect transistor (PMOS), wherein a gate of the first PMOS is coupled to the output voltage port of the OTA, wherein a source of the first PMOS is coupled to a positive power supply;
- and
- a resistor, wherein a first end of the resistor is coupled to a ground, wherein a second end of the resistor is coupled to a drain of the first PMOS and to the feedback voltage input port of the OTA in a feedback net;
- a second PMOS, wherein a gate of the second PMOS is coupled to the output voltage port of the OTA, wherein a source of the second PMOS is coupled to the positive power supply, wherein a drain of the second PMOS is coupled to the bias current input port of the OTA;
- and
- a startup current generator circuit, the startup current generator circuit coupled to the bias current input port of the OTA, the startup current generator circuit to provide a current to the bias current input port when a voltage at the feedback net is below a threshold voltage, and to provide no current to the bias current input port when the voltage at the voltage at the feedback net is above the threshold voltage.
A method, comprising:
- providing, via a startup current generator circuit of a device containing a voltage-to-current converter circuit, a startup current to a bias current input port of an operational transconductance amplifier (OTA) of the voltage-to-current converter circuit, wherein the startup current is provided during a startup of the device;
- generating a bias current via the voltage-to-current converter circuit, the bias current proportional to a reference voltage at a reference voltage input port of the OTA;
- providing the bias current to the bias current input port of the OTA;
- and
- deactivating the startup current generator circuit to cease providing the startup current to the bias current input port when an operational state of the voltage-to-current converter circuit is detected.
Dependencies are inferred from the claim text.