| 摘要 |
An analog-to-digital converter for converting an analog input signal to a digital output signal with m upper bits and n lower bits includes at least 2m+n-1 resistors connected in a series circuit to a voltage source for establishing respective reference voltages; switch elements selectively coupled to the analog input signal and the resistors in response to a switch control signal for supplying a signal indicative of the analog input signal and the respective reference voltages; at least 2m-1 upper bit comparators for generating the switch control signal and output signals indicative of the m upper bits, with first inputs receiving the analog input signal and second inputs connected to the series circuit at intervals defining groups of the resistors; an upper bit encoder receiving the output signals from the upper bit comparators and generating the m upper bits; at least 2n-1 lower bit comparators for generating output signals indicative of the n lower bits, having first and second inputs connected to the switch elements whereby the switch elements selectively supply the signal indicative of the analog input signal to the first inputs and selectively connect the second inputs to the respective resistors in response to the switch control signal; and a lower bit encoder receiving the output signal from the lower bit comparators for generating the n lower bits. |
