OFFSET COMPENSATED DIFFERENTIAL AMPLIFIER AND CALIBRATION CIRCUIT PROVIDING INCREASED LINEAR RANGE AND GRANULARITY OF OFFSET COMPENSATION AND RELATED METHOD

• Main Authors: PRICE, Burt L, LIANG, Jin
• Format: Patent
• Language: English; French; German
• Published: 11.10.2023
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

An offset compensated differential amplifier employing a multi-tan h circuit comprising differential pairs coupled in parallel to compensate for an offset voltage of the output voltage in the offset compensation calibration mode is disclosed. The differential pairs each include a compensation transistor coupled to the positive internal node and a reference transistor coupled to the negative internal node. Each compensation transistor receives the compensation control voltage and each reference transistor receives a different reference voltage. The multi-tan h circuit generates an offset compensation voltage on the positive and negative internal nodes based on a difference between the compensation control voltage and the different reference voltages. The multi-tan h circuit comprises a larger linear range than a hyperbolic tangent current transfer function of a single differential pair. The offset compensated differential amplifier provides offset compensation with improved linearity and a finer granularity compared to a conventional differential amplifier.