Fully-differential preamplifier

A fully-differential preamplifier, comprising:

• an input differential pair, an output current load, and a current source;
• the current source coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the fully-differential preamplifier draws more current when operating in the second mode compared to when operating in the first mode;
• the input differential pair coupled between the output current load and the current source;
• and
• the output current load coupled between a high voltage rail and the input differential pair;
• wherein the input differential pair comprise positive and negative inputs of the fully-differential preamplifier;
• wherein nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier;
• wherein the input differential pair includes first and second N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs), each of which includes a gate, a drain, and a source;
• wherein the output current load includes first and second P-channel MOSFETs, each of which includes a gate, a drain, and a source;
• wherein the sources of the first and second P-channel MOSFETs are connected to one another and to the high voltage rail;
• wherein the drain of the first P-channel MOSFET is coupled to the drain of the first N-channel MOSFET and also comprises the negative output of the fully-differential preamplifier;
• and
• wherein the drain of the second P-channel MOSFET is coupled to the drain of the second N-channel MOSFET and also comprises the positive output of the fully-differential preamplifier.

A fully-differential preamplifier, comprising:

• an input differential pair, an output current load, a current source, and a pair of blanking switches;
• the current source coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the fully-differential preamplifier draws more current when operating in the second mode compared to when operating in the first mode;
• the input differential pair coupled between the output current load and the current source;
• and
• the output current load coupled between a high voltage rail and the input differential pair;
• wherein the input differential pair comprise positive and negative inputs of the fully-differential preamplifier;
• wherein nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier;
• and
• wherein the pair of blanking switches are configured to force a zero voltage differential between the positive and negative inputs of the fully-differential preamplifier, in response to the blanking switches being simultaneously closed.

A fully-differential preamplifier, comprising:

• an input differential pair, an output current load, and a current source;
• the current source coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the fully-differential preamplifier draws more current when operating in the second mode compared to when operating in the first mode;
• the input differential pair coupled between the output current load and the current source;
• and
• the output current load coupled between a high voltage rail and the input differential pair;
• wherein the input differential pair comprise positive and negative inputs of the fully-differential preamplifier;
• wherein nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier;
• wherein the output current load includes first and second P-channel MOSFETs, each of which includes a gate, a drain, and a source;
• wherein the sources of the first and second P-channel MOSFETs of the output current load are connected to one another and to the high voltage rail;
• and
• wherein the output current load further comprises a first capacitor coupled between the gate and the source of the first P-channel MOSFET, and a second capacitor coupled between the gate and the source of the second P-channel MOSFET.

A fully-differential preamplifier, comprising:

• an input differential pair, an output current load, and a current source;
• the current source coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the fully-differential preamplifier draws more current when operating in the second mode compared to when operating in the first mode;
• the input differential pair coupled between the output current load and the current source, wherein the input differential pair comprise positive and negative inputs of the fully-differential preamplifier;
• the output current load coupled between a high voltage rail and the input differential pair, wherein nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier;
• a first high pass filter and a first direct current (DC) blocking capacitor coupled between positive input and a first electrode;
• and
• a second high pass filter and a second DC blocking capacitor coupled between the negative input and a second electrode.