| 摘要 |
The invention discovered a digital technologic attenuate control circuit of current-model step by step. The circuit include a lot of stages of current attenuate circuit; in each of the current attenuate circuit stage, the digital control input point and the common model feeddack circuit input point and the bias voltage point is connected to the digital control signal and the common model feeddack circuit and the bias voltage respectively; the analogue input signal which is introduced in the input circuit is performed attenuate step by step under the control of the digital signal. The circuit is novelty in design, which uses the trans-resistance of MOS transistors forming the equivalent resistance or the matching with current source for performing the attenuate step by step, which avoids relying on resistance matching in art, and controls the implement of attenuate step by step with digital signal directly, and is fast in transform speed and small in phase delay and high precision in control, and is suitable for digital IC manufacture technics.
|
