MC74HC4046A
Phase-Locked Loop
High−Performance Silicon−Gate CMOS
The MC74HC4046A is similar in function to the MC14046 ...
MC74HC4046A
Phase-Locked Loop
High−Performance Silicon−Gate
CMOS
The MC74HC4046A is similar in function to the MC14046 Metal gate
CMOS device. The device inputs are compatible with standard
CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs.
The HC4046A phase−locked loop contains three phase comparators, a
voltage−controlled oscillator (VCO) and unity gain op−amp DEMOUT. The comparators have two common signal inputs, COMPIN, and SIGIN. Input SIGIN and COMPIN can be used directly coupled to large
voltage signals, or indirectly coupled (with a series capacitor to small
voltage signals). The self−bias circuit adjusts small
voltage signals in the linear region of the amplifier. Phase comparator 1 (an exclusive OR gate) provides a digital error signal PC1OUT and maintains 90 degrees phase shift at the center frequency between SIGIN and COMPIN signals (both at 50% duty cycle). Phase comparator 2 (with leading−edge sensing logic) provides digital error ...