Lines with other classes and within this class
The filters proper for this class include at least one active device utilized in producing the transfer function defining the frequencies that will be passed.
A filter in combination with a specific load will be classified in the class providing for the load. See References to Other Classes, below for filtering of data within an electrical digital calculating computer or analog computer.
The filters within the Specific Identifiable Device, Circuit, Or System area (see above) are active filters that suppress an unwanted input signal. See Noise Filters below for additional noise filter areas within Class 327.
Limiting, clipping, or clamping circuits which achieve transient or signal noise reduction by filtering or otherwise are classified in this class.
Compensation for a noise signal which is a by-product of switching thereof is found in this class.
Miscellaneous unwanted signal suppression is classified in this class.
See Subclass References to the Current Class below for these art areas.
PHASE LOCK LOOP
A nonlinear phase lock loop circuit, per se, is classified in Class 327. A phase lock loop circuit in combination with a special art device, is classified with the special art device. For example, a phase lock loop claimed in combination with an oscillator is classified in Class 331, subclasses 172+, a phase lock loop in combination with a telecommunication system is classified in Class 455, and a phase lock loop in combination with a pulse or digital communication system is classified in Class 375, subclasses 111+.
See Subclass References to the Current Class below for a phase lock loop to synchronize one signal with another for the creation of a replica signal.
Digital logic, per se, is classified in Class 326 and this includes, for example, multiple connections of AND, OR, or NOT gates. However, combinations of multiple AND or OR gates, etc., which perform a particular function proper to some other class are classified in that other class. For example, an AND gate claimed to be used as a comparator, for example, will be classified in Class 327, whereas a claimed AND gate, per se, would be classified in Class 326.
Patents reciting a free running astable multivibrator, per se, are classified elsewhere. For example, see References to Other Classes for a relaxation oscillator multivibrator.
Multivibrators having one or more stable states are classified in Class 327. See Subclass References to the current Class.
Generally, detailed flip-flops, per se, are in this class, subclasses 185+; however, multifunctional or programmable logic having a flip-flop is in Class 326, subclasses 37+ and redundant logic having a flip-flop is in Class 326, subclass 12.
An integrated circuit chip, per se, is classified in Class 257.
Lead frames, per se, are classified in Class 257 since these are only used to connect an integrated circuit chip externally.
An integrated circuit chip in combination with a single lead, a battery or bias without any additional circuit configuration, is classified in Class 257.
An integrated circuit chip in combination with an external circuit proper for Class 327 will be classified in Class 327 since Class 327 is higher than Class 257 in the overall class hierarchy.
Circuit interconnections (e.g., point to point, lead interconnections, diode and transistor interconnections, etc.) within the confines of the integrated circuit chip itself are classified in Class 257, whereas circuit interconnections outside the environment of an integrated circuit chip are not.
If an integrated circuit is recited with other than a nominal recitation of a utility, the patent will be classified in the utility class.
CHARGE COUPLED DEVICES
CCD"s recited as part of the circuitry within an integrated circuit chip are classified in Class 257.
CCD"s recited with other than a nominal recitation of utility are classified in the utility class. See References to Other Classes, below.
Power supplies in combination with another art device, classifiable elsewhere, will be found with the other art device. Tubes or solid-state device power supplies for a nonlinear device, circuit, or system, not elsewhere classified, will remain in this class (327).
A power supply in combination with a load, (i.e., a single power supply and a single load) without any claim to a substrate circuit is classified elsewhere. See References to Other Classes, below.
The power supply patents of this class, subclasses 530+ require a nonlinear device, circuit, or system as a load or control for the power supply. A claim to a power supply circuit in combination with a substrate containing a nonlinear device, circuit, or system is classified in Class 327.
SYSTEMS WITH SPECIFIC SOURCE OF INPUT ENERGY ONLY IDENTIFIED BY CHARACTERISTIC
This class does not provide for the subject matter included herein in combination with a specific type of electromagnetic wave energy since the broad recitation of the specific source would be classifiable with the art containing that particular source of energy. However, this class will take the systems and networks of the class in combination with a source of wave energy wherein the energy is expressed only as being composed of a band of frequencies or a source of pulses, etc., or wherein the source is recited by name only as a wave energy generator (such as an oscillator, pulse generator, etc.). Where the specific details of the source are recited such systems are classified with the art which provides for systems utilizing such specific source.
Claims to a specific mechanical structure in combination with generic circuitry are classified with the mechanical structure. However, claims to broad mechanical structure in combination with specific circuitry is classified in this class unless provided for in a mechanical or electrical class and provided the circuitry is nonlinear.
A generic nonlinear circuit claimed with a memory inside the circuit is classified in this class (327), whereas a claim to generic circuitry in combination with a memory external to the circuit would be classified with the memory class.
MONITORING, TEST OR CALIBRATING
The following areas reciting monitoring, testing or calibrating take precedence over Class 327:
Class 73, subclasses 1.01+ for instrument proving or calibrating; and subclass 865.9 for testing of apparatus.
Class 324, subclass 601 for calibration, and subclasses 74+ for testing and calibrating of electric meters.
Class 342, subclasses 165+ for testing or calibrating a radar system.
Class 348, subclasses 180+ for television monitoring or testing.
Class 358, subclass 406 for facsimile measuring or testing.
Class 374, subclasses 1+ for thermal measuring and testing.
Class 455, subclass 115 for measuring, testing or monitoring of a transmitter and subclass 226 for measuring, testing, or monitoring of a receiver. Only monitoring, testing, or calibrating, not elsewhere classified, and related to nonlinear devices, circuits and systems are classified in Class 327. The following are examples of those found in Class 327: subclasses 20, 262, 292, 378, 509, and 538.
Class 600, subclass 486 for testing means inserted in the human body.
Class 702, appropriate subclasses for testing and measuring which includes a computation.
Only those nonlinear circuits or systems whose function is not specifically provided for elsewhere would be classified in this class (327) subclasses 334+.
See References to Other Classes, below for examples of other areas for switching;
CIRCUITS WITH ELECTRON OR OTHER CHARGED PARTICLE BEAM TUBE
Only those nonlinear circuits utilizing electron or other charged particle beams that are not classifiable in other areas would be classified in Class 327.
Examples of electron or other charged particle beam tube circuits classified elsewhere are the cyclotron and CRT circuits of Class 313.
MODULATION OR COMMUNICATION
Nonlinear circuits used in combination with a modulated signal are classified in the classes containing the communication of information via a modulated signal.
ELECTRICAL CONTROL OF MACHINES
Electrical control with a broad machine is classified with the machine, if a class exists for the machine. Only those electrical control patents, not provided for in the machine classes, would be classified in Class 327, provided the circuit is nonlinear.
NEURON CIRCUITS OR NETWORKS
Patents reciting neuron simulator circuitry, per se, and neural networks are classified elsewhere. See References to Other Classes below.
FUSIBLE LINK AND INTENTIONAL DESTRUCT CIRCUIT
Miscellaneous circuits of this type are classified in this class (327) subclass 525.
Free running oscillators (including the asynchronous type) are classified elsewhere. See References to Other Classes below.
PERSONNEL OR DEVICE PROTECTIVE CIRCUITS
Circuits used to protect personnel from harm, or protect devices from failure (e.g., overload, power surge) are excluded from this class. See References to Other Classes below.
SYSTEMS WITH SPECIFIC LOADS IN THE OUTPUT CIRCUIT
This class does not provide for the subject matter in combination with a specific load device even though the load device is recited by name only (as a motor, loud-speaker, etc.). Such systems are classified in general with the particular art device constituting the load.
This class does not include electronic circuits, per se, wherein a variable electric current or voltage input signal is applied to an electrical amplifying device to control a source of electrical energy applied to the same device, and from which is derived an output signal of substantially the same waveform as the input signal and substantially linearly related thereto.
LINEAR DEVICE, CIRCUITS OR SYSTEMS
This class excludes linear resistors, reactive apparatus and insulators, per se. Although the claimed solid-state device may be active or passive and have some insulative or reactive properties, it cannot be classified in this class if the device is generally thought of as being only an insulator or reactive apparatus such as a capacitor, inductor, transformer, motor, etc.
See References to Other Classes for electrical pulse counters, pulse dividers, or shift registers.
See References to Other Classes for filters utilizing lumped or distributed parameter passive elements.
SPECIAL ART DEVICES
Special art devices are to be classified with the specified device.
Circuitry utilizing gas tubes not elsewhere provided for are included here. See, Subclass References To The Current Class, below, for an example.