Fully integrated all-CMOS AM receiver

A radio receiver formed as a monolithic integrated circuit comprising:

• a superheterodyne receiver having an input coupled to an antenna input of said integrated circuit, said receiver including an intermediate frequency (IF) filter for providing an IF filtered output;
• a demodulator for receiving said IF filtered output and outputting a digital data signal, said demodulator including a baseband filter;
• said superheterodyne receiver and said demodulator being formed entirely on a single monolithic integrated circuit chip using CMOS transistors, said intermediate frequency filter and said baseband filter being formed entirely on said chip;
• a reference oscillator, said intermediate frequency filter having filtering characteristics controlled by an output of said reference oscillator;
• and
• a bias level generator, said bias level generator including a phase locked loop (PPL) circuit connected to said reference oscillator, said reference oscillator providing a reference frequency for said PPL circuit, said bias level generator generating a control signal needed to achieve frequency lock in said PPL circuit with said reference frequency, said control signal generating a bias signal coupled to said intermediate frequency filter to control said filtering characteristics.