The MX315A is a monolithic CMOS tone encoder for sub-audible tone squelch systems, which provides three additional frequencies over the earlier MX315A. These frequencies are 69.3, 97.4 and 206.5Hz. The tone frequencies are derived from an input reference frequency. An on-chip inverter is provided to drive an external crystal circuit.
Tone selection is achieved through six programming inputs and two control inputs (which allow either a logic “1” or “0” to enable the device). A low distortion sinewave is generated at the TX Tone Output when the MX315A is enabled. The emitter follower output stage can source 1mW directly into a 600Ω load (0dBm).
The MX315A is available in the following package styles: 16-pin SOIC (MX315ADW), 14-pin PDIP (MX315AP) and 14-pin CDIP (MX315AJ).

FEATUREs
• Field Programmable Tone Encoder
• 40 CTCSS Frequencies
• Crystal-Controlled Frequency Stability
• Low Distortion Sinewave Output
• Few External Components Required
• CMOS Low Power Requirements

APPLICATIONs
• Mobile Radio Base Stations & Repeater Stations
• Mobile Radios
• Hand-Held Radios
• Industrial Controls
• Intercom Systems
• Door-Entry Systems