NE567 Tone Decoder Phase-Locked Loop IC

The NE567 tone and frequency decoder designed as a highly stable phase-locked loop with synchronous AM lock detection and power output circuitry. The most important function of PLL is to drive a load whenever a sustained frequency within its detection band present at the self-biased input. It operates in a wide frequency range 0.1 to 500 kHz providing high stability of center frequency. Along with Independently controllable bandwidth (up to 14%). Meanwhile, this device features high out-band signal and noise rejection Logic-compatible output with 100 mA current-sinking capability. Also, provide Inherent immunity to false signals and Frequency adjustment over a range 20-to-1 range with external components.

When NE567 functions as a tone-operated switch, its output switching delay are often varied over a good time range by the choice of external resistors and capacitors. The current-controlled oscillator of the 567 are often varied over a good frequency range with external resistor R1 and capacitor C1, but the oscillator are often controlled only over a really narrow range (a maximum of about 14% of the free-running value) by signals at pin 2. As a result, the PLL circuit can “lock” only to a really narrow range of preset input frequency values. The 567’s quadrature phase detector compares the relative frequencies and phases of the input and therefore the oscillator output. It produces a legitimate output.

APPLICATIONS:

• Touch-Tone decoding
• Carrier current remote controls
• Ultrasonic controls (remote TV, etc.)
• Communications paging
• Frequency monitoring and control
• Wireless intercom
• Precision oscillator