NE564N

NE564N Phase-Locked Loop (PLL) Technical Summary

Overview

The NE564N is a high-performance phase-locked loop (PLL) integrated circuit designed for operation up to 50MHz. This versatile component is part of the NE/SE564 family, which is widely used in communication and signal processing applications. The device integrates a voltage-controlled oscillator (VCO), limiter, phase comparator, and other critical PLL components into a single package, making it suitable for high-speed modulation, demodulation, and frequency synthesis tasks. The NE564N operates on a single 5V supply and features TTL-compatible inputs and outputs, ensuring easy integration with digital systems.

Features

• Operation with a single 5V power supply
• TTL-compatible inputs and outputs for seamless digital interfacing
• Guaranteed operation up to 50MHz
• External loop gain control for flexible system tuning
• Reduced carrier feedthrough for improved signal integrity
• No elaborate filtering required in FSK (Frequency Shift Keying) applications
• Can function as a modulator for various communication schemes
• Variable loop gain, adjustable via external control

Applications

• High-speed modems for data communication
• FSK (Frequency Shift Keying) receivers and transmitters
• Frequency synthesizers for stable clock generation
• Signal generators for test and measurement equipment
• Satellite communication (Satcom) and TV broadcast systems

Electrical Characteristics

The NE564N is designed to operate under the following electrical conditions:

• Supply Voltage (V+): 5V (single supply operation)
• Operating Frequency Range: Up to 50MHz (guaranteed)
• Input Compatibility: TTL-level signals for control and modulation inputs
• Output Drive Capability: TTL-compatible outputs for direct digital interfacing
• Loop Gain Control: Adjustable via external components for system optimization

Package Information

The NE564N is available in multiple package options to suit different application requirements:

• 16-Pin Plastic Dual In-Line Package (DIP): NE564N (0°C to +70°C)
• 16-Pin Plastic Small Outline (SO) Package: NE564D (0°C to +70°C)
• Extended Temperature Range DIP: SE564N (-55°C to +125°C)

Pin Configuration

The NE564N features a 16-pin configuration with the following key pin functions:

• Pin 1 (V+): Positive supply voltage input
• Pin 10 (GND): Ground reference
• Pin 14 (FM/RF Input): Frequency modulation or RF signal input
• Pin 6 (TTL Output): TTL-compatible output signal
• Pin 9 (Analog Out): Analog output from the PLL
• Pin 11 (VCO Out): Voltage-controlled oscillator output
• Pins 4-5 (Loop Filter): External loop filter connections
• Pins 12-13 (Frequency Set Capacitor): External capacitor for VCO frequency setting

Block Diagram Overview

The internal architecture of the NE564N includes:

• Voltage-Controlled Oscillator (VCO): Generates the output frequency based on control voltage
• Phase Comparator: Compares input and feedback signals to generate error voltage
• Limiter: Provides amplitude stabilization of input signals
• Schmitt Trigger: Provides digital signal conditioning
• DC Amplifier: Amplifies the error signal for VCO control
• Post Detection Processor: Additional signal processing for demodulation applications

Absolute Maximum Ratings

The NE564N must not be operated beyond these limits:

• Supply Voltage (V+): 14V maximum (pins 1 and 10)
• Output Current: Maximum sink (pin 9) and source (pin 11) currents as specified
• Operating Temperature Range: 0°C to +70°C for NE564N, -55°C to +125°C for SE564N
• Storage Temperature Range: -65°C to +150°C

Design Considerations

When implementing the NE564N in a circuit design, consider the following:

• Proper bypass capacitors should be used near the power supply pins
• The loop filter components should be selected based on desired loop bandwidth
• Frequency setting capacitors should have low temperature coefficients for stable operation
• PCB layout should minimize parasitic capacitance and inductance in high-frequency paths
• For FSK applications, the internal limiter eliminates the need for additional filtering

Ordering Information

The NE564N is available through various ordering codes:

• NE564D: 16-pin SO package (0°C to +70°C), Drawing # SOT109-1
• NE564N: 16-pin DIP package (0°C to +70°C), Drawing # SOT38-4
• SE564N: 16-pin DIP package (-55°C to +125°C), Drawing # SOT38-4

Conclusion

The NE564N phase-locked loop represents a robust solution for high-frequency communication and signal processing applications. Its combination of high operating frequency, flexible loop gain control, and TTL compatibility make it particularly suitable for modern communication systems. The device's ability to function as both a modulator and demodulator, along with its reduced carrier feedthrough characteristics, provides designers with a versatile component for various RF and digital communication applications. With proper implementation following the recommended design guidelines, the NE564N can deliver reliable performance in demanding frequency control and signal recovery applications.