Description
The CD22204 complete dual tone multiple frequency (DTMF) receiver detects a selectable group of 12 or 16 standard digits. No front-end pre-filtering is needed. The only externally required components are an inexpensive 3.579545MHz TV ‘‘colorburst’’ crystal (for frequency reference) and a bias resistor. Extremely high system density is possible through the use of the Alternate Time Base (ATB) output of a crystal connected CD22204 receiver to drive the time bases of up to 10 additional receivers. This is a monolithic integrated circuit fabricated with low power, complementary symmetry CMOS processing. It only requires a single power supply.

FEATUREs
• No Front End Band Splitting Filters Required
• Single Low Tolerance 5V Supply
• Three-State Outputs for Microprocessor Based Systems
• Detects all 16 Standard DTMF Digits
• Uses Inexpensive 3.579545MHz Crystal
• Excellent Speech Immunity
• Output in 4-Bit Hexadecimal Code
• Excellent Latch-Up Immunity