Texas Instruments Corporation

Texas Instruments Tucson Corporation

David M Jones

Jerry Doorenbos

Jeffrey B Parfenchuck

Vadim Valerievich Ivanov

Mikhail Valeryevich Ivanov

R Mark Stitt, Ii

Stephen James Sanchez

David Alexander Gammie

David R Spady

Heinz-Juergen Metzger

A method and circuit is provided for improving the control of the trimming procedure for various devices without the need for additional dedicated control pins. Instead, the trimming procedure is controlled through sensing of changes in current and/or voltage applied through the existing available pins or bondpads of the devices to determine whether a command for trim programming has occurred. As a result, package-level trimming of the devices can be conducted in standard device packages having low pin count configurations, such as operational amplifiers, instrumentation amplifiers, difference amplifiers, low drop-out regulators, voltage references and other similar types of devices. A device to be trimmed is configured with internal circuitry configured to sense changes in current and/or voltage in the output or supply voltage of the device, and a test system for applying changes in the current and/or voltage through the existing available pins or bondpads of the devices. The internal circuitry can comprise sensing circuitry comprising one or more internal sensors configured to measure current and/or voltage in the output or supply voltage of the device, and can comprise trim programming circuitry for facilitating trim programming of the device.

Method and circuit for improving control of trimming procedure

An operational amplifier having an adjustable input offset is provided that can improve dynamic performance by allowing processing of the input signal in continuous-time. The amplifier circuit comprises an input source and an operational amplifier configured with an adjustable input offset circuit. The adjustable input offset circuit enables cancellation of the offset error from any input sources prior to being translated or gained up by the operational amplifier, thus improving the dynamic range of the operational amplifier. The adjustable input offset circuit can be configured within a signal path of an auto-zero loop of the operational amplifier, or with a continuous-time implementation.

Operational amplifier with adjustable input offset

A leakage compensation circuit and technique is provided that compensates for losses in a referenced current of an amplifier circuit due to leakage elements. The leakage compensation circuit is configured to inject current substantially equal in magnitude to the leakage current into one or more junctions of the amplifier circuit to compensate for lost referenced current due to leakage. As a result, the amplifier circuit and various devices can realize the flow of the reference current as substantially intended without detrimental effects of leakage current, thus maintaining the integrity of the referenced current. The leakage compensation circuit comprises an array of compensation regions configured to approximate the collective loss that is created by the leakage elements and provide a compensation current substantially equal in magnitude to one or more junctions to compensate for lost referenced current.

Current leakage compensation circuit and method

A current sense amplifier ( ) for measuring current flowing through a sense resistor ( ) coupled between first ( ) and second ( ) terminals, respectively, of the current sense amplifier, the current sense amplifier includes a first amplifier ( ) having a first input ( ) coupled by a first resistor ( ) to the first terminal ( ) and a second input ( ) coupled by a second resistor ( ) to the second terminal ( ) and a bias circuit ( ) coupled to the first input ( ) of the first amplifier for causing the bias current to flow through the first resistor ( A feedback transistor ( ) is coupled to the output ( ) of the first amplifier and the second input ( ) of the first amplifier to cause a feedback current to equalize the voltages on the first ( ) and second ( ) inputs of the first amplifier and supply the feedback current to an output terminal ( ) of the current sense amplifier ( ).

Current sense amplifier and method

A temperature-compensated monolithic logarithmic amplifier includes a logarithmic amplifier cell ( ) configured to produce a logarithmic voltage signal (V ) representative of a difference between a first voltage (V ) developed across a first PN junction device (D ) in response to an input signal (I ) and a second voltage (V ) developed across a second PN junction device (D ) in response to a reference signal (I ) and an output circuit ( ) including an output amplifier ( ), a temperature-dependent first resistive element (R ) having a positive temperature coefficient, and a second resistive element (R ). The output circuit ( ) produces a temperature-compensated output signal (V ) in response to the logarithmic voltage signal (V ). The first resistive element (R ) is composed of conductive aluminum or aluminum alloy interconnection metallization that also is utilized as interconnection metallization throughout the monolithic logarithmic amplifier.

Method and circuit for compensating VT induced drift in monolithic logarithmic amplifier

A temperature curvature compensation technique and circuit can be realized through the generation of a temperature curvature compensation voltage provided by measuring the difference between the base-emitter voltage V,of two different transistors operating at two different temperature coefficient quiescent currents. This voltage difference measured between two such transistors results in a scaled voltage that is representative of the temperature curvature of the base-emitter voltage V,of a transistor, and which can then be summed to the bandgap reference output to provide a temperature compensated, bandgap reference voltage. The above method can be carried out in an amplifier circuit configured to receive and sum the temperature curvature compensation voltage and the bandgap reference output voltage into the temperature compensated, bandgap reference voltage. In addition, the summing of the temperature curvature compensation voltage and the bandgap reference output voltage may be realized through the application of a dual differential pair amplifier configuration which operates as a g,source. Further, scaling of the respective input voltages for each differential pair can be provided by the amplifier circuit. Moreover, the dual differential pair amplifier may be incorporated into a buffer amplifier configuration to receive a bandgap reference voltage and provide a buffered output or, integrated with a bandgap reference circuit directly into an amplifier circuit.

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Tucson, AZ, United States of America

David M Jones