| 摘要 |
PURPOSE:To decrease the chip size and to increase the accuracy, without buffer amplifier, by using the resistor ladder to set a step voltage. CONSTITUTION:By changing over the switches 7-10 to the position 2, the input signal VIN from the analog signal terminal 1 is stored in the capacitors 3-6 via the switch 2. Next, the switch 2 is changed over to ground, the polarity of input signal is determined by opening the switch 11, and the polarity is stored to the polarity latch circuit 26 by controlling the switch 24. Next, the operation of sequential comparison is started. The 4 sets of segments near the zero level perform sequential comparison operation with the voltage of VREF/17 obtained from the resistor ladder, and the four segments greater than the voltage perform the sequential comparison operation at the reference voltage VREF. |
