Low-Power Dual Tone Multiple Frequency Receiver

The MC145436A is a low–power and improved input sensitivity version of the MC14LC5436. The MC145436A is a silicon gate CMOS LSI device containing the filter and decoder for detectionof a pair of tones conforming to the DTMF standard with outputsin hexadecimal. Switched capacitor filter technology is used together withdigital circuitry for the timing control and output circuits. The MC145436A providesexcellent power line noise and dial tone rejection and is suitable for applicationsin central office equipment, PABX, and keyphone systems, remote
control equipment and consumer telephony products.
The MC145436A offers the following performance features:

• Single + 5 V Power Supply
• Detects All 16 Standard Digits
• Uses Inexpensive 3.58 MHz Crystal
• Provides Guard Time Controls to Improve Speech Immunity
• Output in 4–Bit Hexadecimal Code
• Built–In 60 Hz and Dial Tone Rejection
• Pin Compatible with SSI–204, MC145436, and MC14LC5436
• Functional and Applicational Compatible with MC145436 and MC14LC5436