| 摘要 |
A sample hold amplifier in which the circuit output tracks the voltage input, and, in response to a command signal, samples and accurately holds the sampled input voltage at the amplifier output. In this SHA, both the input and the output are buffered, and the input voltage is sampled not only across a primary ''hold'' capacitor (18), but also across a secondary ''hold'' capacitor (20) at the output of the amplifier, so as to reduce voltage excursions at the output of the circuit due to buffer offsets. The input and output buffers introduce complementary, equal magnitude offset voltages which, together with a unique feedback arrangement to control charging of the output amplifier capacitor, enables auto-zeroing of internal amplifier offset errors. |
