Complementary current reusing preamp for operational amplifier
AssigneeTexas Instruments Incorporated
InventorTien-Ling HSIEH
Life of this patent
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Abstract
An apparatus includes a preamplifier stage to receive a power supply voltage and generate an output based upon an input. In particular, the preamplifier stage includes a biasing device coupled between the output and a ground node to bias a DC voltage level of the output independently of the power supply voltage. The preamplifier stage also includes a complementary circuit to receive the input and generate the output. The complementary circuit reuses a current through the preamplifier stage to provide an increased transconductance of the preamplifier stage for a given current level.
Claims20
An apparatus comprising:
- a preamplifier stage to receive a power supply voltage and generate an output based upon an input, the preamplifier stage comprising:
- a biasing device coupled between the output and a ground node to bias a DC voltage level of the output independently of the power supply voltage;
- a complementary circuit to receive the input and generate the output, wherein the complementary circuit reuses a current through the preamplifier stage to provide an increased transconductance of the preamplifier stage for a given current level.
A method comprising:
- receiving, by a preamplifier stage, a power supply voltage and an input;
- generating, by the preamplifier stage, an output based upon the input;
- biasing a DC voltage level of the output independently of the power supply voltage;
- and
- reusing, by a complimentary circuit, a current through the preamplifier stage to increase transconductance of the preamplifier stage for a given current level.
An analog-to-digital converter comprising:
- a preamplifier stage to receive a power supply voltage and generate an output based upon an input, the preamplifier stage comprising:
- a diode-connected device coupled between the output and a ground node to bias a DC voltage level of the output independently of the power supply voltage;
- a complementary circuit to receive the input and generate the output, wherein the complementary circuit comprises:
- a PMOS differential pair coupled to a power supply side of the preamplifier stage;
- and
- an NMOS differential pair coupled to a ground side of the preamplifier stage, wherein the complimentary circuit reuses a current through the preamplifier stage to provide an increased transconductance of the preamplifier stage for a given current level;
- a telescopic amplifier stage coupled to the preamplifier stage to receive and amplify the output of the preamplifier stage producing an amplified output;
- and
- analog-to-digital conversion logic to receive the amplified output of the telescopic stage and generate a digital signal based on the received, amplified output of the telescopic amplifier stage.
Dependencies are inferred from the claim text.