| 摘要 |
A differential amplifier that has a current supply and a differential current to voltage converter with a positive current input node, a negative current input node and a voltage output node, has offset voltage trimming. The voltage output node provides an output voltage that is proportional to the difference in current values flowing into the positive current input node and a negative current input node. A trimming circuit has a plurality of trimming control inputs, an inverting trimming output, a non-inverting trimming output and trimming inputs coupled to the current supply. Trimming resistances couple the inverting trimming output to the non-inverting trimming output. Trimming selectors, controllable by a trim code provided to the trimming control inputs, provide for selectively connecting the current supply directly to the non-inverting trimming output while selectively connecting the current supply to the inverting trimming output through a first selected group of the trimming resistances. The differential amplifier also has a differential transistor pair formed by an inverting transistor that couples the inverting trimming output to the positive current input node and a non-inverting transistor that couples the non-inverting trimming output to the negative current input node.
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