Nonetheless, it had superior performance compared with the 3705 : it was 5 times faster, it had about 100 times less leakage current, and the on resistance of the large transistors making up the analog switches was 3 times lower.
22.
Some manufacturers released some 4000 equivalent CMOS circuits with a 74 prefix, for example the 74HC4066 was a replacement for the 4066 with slightly different electrical characteristics ( different power supply voltage ratings, higher frequency capabilities, lower " on " resistances in analog switches, etc . ).
23.
During the early 1970s, telephone companies began to phase out the older electromechanical switching systems such as the step-by-step circuit switching systems and replace them with newer electronic switching systems that were controlled by proprietary computers but still used analog switch fabrics such as Bell-proprietary ferreed switch devices.
24.
Digital is way more compact than analog because signal compression is easily employed . ( See Digital _ television # Advantages _ to _ conversion : " Citing the bandwidth efficiency of digital TV, after the analog switch-off, the FCC will auction off channels 52-69 ( the lower half of the 700 MHz band ) for other communications traffic, " ).
