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US 10,044,362 B2Granted
Complementary current reusing preamp for operational amplifier
AssigneeTexas Instruments Incorporated
InventorTien-Ling Hsieh
Life of this patent
Estimating the term…
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.
Claims6
An apparatus comprising:
- a preamplifier stage including:
- a first output;
- a second output;
- a current source;
- a PMOS differential pair coupled to a power supply side of the preamplifier stage, sources of the PMOS differential pair being coupled to the current source;
- an NMOS differential pair coupled to a ground side of the preamplifier stage, a drain of a first NMOS transistor in the NMOS differential pair being coupled to a drain of a first PMOS transistor in the PMOS differential pair and to the first output, a drain of a second NMOS transistor in the NMOS differential pair being coupled to a drain of a second PMOS transistor in the PMOS differential pair and to the second output;
- and
- a first diode-connected device coupled between the first output and a ground node;
- and
- a second diode-connected device coupled between the second output and the ground node;
- wherein the preamplifier stage further comprises a cross-coupled circuit coupled to the first diode-connected device to adjust a gain of the preamplifier stage.
8 more elements
The An apparatus comprising:
- a preamplifier stage including:
- a first output;
- a second output;
- a current source;
- a PMOS differential pair coupled to a power supply side of the preamplifier stage, sources of the PMOS differential pair being coupled to the current source;
- an NMOS differential pair coupled to a ground side of the preamplifier stage, a drain of a first NMOS transistor in the NMOS differential pair being coupled to a drain of a first PMOS transistor in the PMOS differential pair and to the first output, a drain of a second NMOS transistor in the NMOS differential pair being coupled to a drain of a second PMOS transistor in the PMOS differential pair and to the second output;
- a first diode-connected device coupled between the first output and a ground node;
- and
- a second diode-connected device coupled between the second output and the ground node;
- and
- a feedback loop coupled to the preamplifier stage, wherein the feedback loop controls a gate voltage of a short-channel device wherein the short-channel device is coupled to the sources of the PMOS differential pair;
- wherein the preamplifier stage further comprises a resistive feedback circuit coupled to the first diode-connected device to adjust a gain of the preamplifier stage.
9 more elements
An analog-to-digital converter comprising:
- a preamplifier stage including:
- an output including a first output node and a second output node;
- a complementary circuit including:
- a current source;
- a PMOS differential pair coupled to a power supply side of the preamplifier stage, sources of the PMOS differential pair being coupled to the current source;
- and
- an NMOS differential pair coupled to a ground side of the preamplifier stage, a drain of a first NMOS transistor in the NMOS differential pair being coupled to a drain of a first PMOS transistor in the PMOS differential pair and to the first output node, a drain of a second NMOS transistor in the NMOS differential pair being coupled to a drain of a second PMOS transistor in the PMOS differential pair and to the second output node;
- a first diode-connected device coupled between the first output node and a ground;
- and
- a second diode-connected device coupled between the second output node and the ground, the analog-to-digital converter further comprising:
- 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;
- wherein the preamplifier stage further comprises a cross-coupled circuit coupled to the first and second diode-connected devices to adjust a gain of the preamplifier stage.
11 more elements
An apparatus comprising:
- a preamplifier stage including:
- a first output;
- a second output;
- a current source;
- a PMOS differential pair coupled to a power supply side of the preamplifier stage, sources of the PMOS differential pair being coupled to the current source;
- an NMOS differential pair coupled to a ground side of the preamplifier stage, a drain of a first NMOS transistor in the NMOS differential pair being coupled to a drain of a first PMOS transistor in the PMOS differential pair and to the first output, a drain of a second NMOS transistor in the NMOS differential pair being coupled to a drain of a second PMOS transistor in the PMOS differential pair and to the second output;
- and
- a first diode-connected device coupled between the first output and a ground node;
- and
- a second diode-connected device coupled between the second output and the ground node;
- wherein the preamplifier stage further comprises a first resistive feedback circuit coupled to the first diode-connected device and a second resistive feedback circuit coupled to the second diode-connected device to adjust a gain of the preamplifier stage.
8 more elements
A method comprising:
- receiving, by a preamplifier stage, a power supply voltage and a differential input;
- generating, by the preamplifier stage, an output based upon the differential input;
- reusing, by a complimentary circuit, a current through the preamplifier stage, the complementary circuit including 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, sources of the PMOS differential pair being coupled to a current source, a drain of a first NMOS transistor in the NMOS differential pair being coupled to a drain of a first PMOS transistor in the PMOS differential pair and to a first output node, a drain of a second NMOS transistor in the NMOS differential pair being coupled to a drain of a second PMOS transistor in the PMOS differential pair and to a second output node;
- biasing the first output node with a first diode-connected device coupled between the first output node and a ground node;
- and
- biasing the second output node with a second diode-connected device coupled between the second output node and the ground node;
- further comprising adjusting a gain of the preamplifier stage using a first resistive feedback circuit coupled to the first diode-connected device and a second resistive feedback circuit coupled to the second diode-connected device.
4 more elements
Dependencies are inferred from the claim text.