Method and apparatus switches the low-voltage CMOS switch of high-voltage digital / analog converter in

摘要

(57) Abstract In order to make wide-ranging analog reference voltage and power supply voltage conform making use of the variable power source range which can exceed the surrender voltage of the switch inside DAC, it was locked substantially, it is lower than surrender voltage, the righteousness and negative formation OFF voltage are formed. The digital input signal which possesses digital input level, is received by the TTL/CMOS input receiver, level is shifted in the logical level which possesses the righteousness and negative formation voltage level. The circuit makes switch resistance match, forms the righteousness and negative switch ON voltage level, forms the voltage level of input correct analog reference level and input negative analog reference level. The switch driver, drives the control terminal of the switch appropriately at the appropriate voltage level which evades the surrender of the switch according to the digital input signal.