| 摘要 |
A amplifier (21) having increased linearity, low input impedance, and low noise is provided. The amplifier (21) has an input (22), a bias input, a first output (23), and a second output (33). A first transistor (26) has a collector coupled to the first output (23), a base coupled to the bias input, and an emitter. A first resistor (27) is coupled between the emitter of the first transistor (26) and the input (22). A second transistor (29) has a collector and base coupled in common, and an emitter coupled for receiving a power supply voltage. A second resistor (28) couples between the input (22) and the common base and collector of the second transistor (29). A third transistor (32) has a collector coupled to the second output (33), a base coupled to the common base and collector of the second transistor (29), and an emitter coupled for receiving the power supply voltage. An input signal applied to the input (22) generates a differential current at the first and second outputs (23, 33). The input signal and the differential current have a linear relationship.
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