Adaptive amplifier circuit with enhanced dynamic range
First Claim
Patent Images
1. A photodetector amplifier circuit comprising:
- a photodetector;
an input transistor connected to the photodetector;
an integration capacitor;
an adaptive skimming circuit connected to the integration capacitor; and
a switched-capacitor low-pass filter connected to the output of the input transistor.
10 Assignments
0 Petitions
Accused Products
Abstract
An adaptive amplifier circuit with minimal excess noise and a linear charge-handling capacity exceeding 109 electrons to enable high-quality imaging at long wavelength infrared backgrounds and video frame rates with enhanced dynamic range is disclosed. An integration capacitor stores a charge produced from a photodetector. An adaptive skimming circuit skims off excess charge during integration of the charge on the integration capacitor. A switched-capacitor low pass filter provides enhanced dynamic range.
63 Citations
11 Claims
-
1. A photodetector amplifier circuit comprising:
-
a photodetector;
an input transistor connected to the photodetector;
an integration capacitor;
an adaptive skimming circuit connected to the integration capacitor; and
a switched-capacitor low-pass filter connected to the output of the input transistor. - View Dependent Claims (2, 3, 4, 5)
first and second transistors connected to the output of the input transistor;
a filter capacitor having one node connected to the first and second transistors; and
an output capacitor having a node connected to the second transistor and an output node.
-
-
5. The circuit of claim 4, further comprising a negative feedback amplifier connected between the photodetector and the input transistor, wherein the photodetector is a low impedance detector.
-
6. A focal plane array (FPA) having a plurality of pixel cells, each pixel cell comprising:
-
an input transistor;
a photodetector coupled to the source of the input transistor;
an adaptive skimming circuit connected to the input transistor, the adaptive skimming circuit comprising an integration capacitor for storing a charge proportional to an amount of incident light on the photodetector; and
a switched-capacitor low-pass filter connected to an output of the input transistor;
wherein the switched-capacitor low-pass filter increases a dynamic range of the circuit.
-
-
7. An amplifier circuit for coupling infrared (IR) detectors to multiplexing readouts, the circuit comprising:
-
detector means for converting incident light to an input electric signal;
signal input means for transferring the input electric signal from the detector means;
storage means for storing a charge from the detector; and
skimming means for skimming off a predetermined level of the input electrical signal; and
low pass filter means for increasing a dynamic range of the amplifier circuit.
-
-
8. An amplifier circuit for coupling infrared (IR) detectors to multiplexing readouts, the circuit comprising:
-
an input transistor;
a detector coupled to a source of the input transistor;
an adaptive skimming circuit connected to the input transistor, comprising an integration capacitor;
a first switch transistor having a source connected to the drain of the input transistor;
a second switch transistor having a source connected to a drain of the first switch transistor, and a drain connected to an output node;
a filter capacitor having a node connected to the drain of the first switch capacitor; and
an output capacitor having a node connected to the drain of the second switch capacitor. - View Dependent Claims (9, 10, 11)
-
Specification