The U2100B is a PLL (Phase-Locked Loop) FM receiver circuit designed by Atmel (now Microchip Technology). It's a monolithic integrated circuit designed for use in cordless telephones, FM radios, and other applications that require FM demodulation. The U2100B offers a complete FM receiver function, including local oscillator, mixer, IF amplifier, and FM demodulator, all integrated onto a single chip.

Applications:

• Cordless telephones: Used in the receiver section of cordless telephones to demodulate the FM signal transmitted from the base station.
• FM radios: Employed as the core FM receiver in portable radios and other FM radio applications.
• Wireless microphones: Used in wireless microphone receivers to demodulate the FM signal transmitted from the microphone.
• Remote control systems: Applied in remote control systems to demodulate FM signals transmitted from the remote control transmitter.
• Wireless audio systems: Used in wireless audio systems to demodulate FM signals transmitted from the audio source.

Features:

• Complete FM receiver function: Integrates all necessary functions for FM demodulation, including local oscillator, mixer, IF amplifier, and FM demodulator.
• PLL frequency synthesizer: Uses a phase-locked loop (PLL) frequency synthesizer to generate a stable and accurate local oscillator frequency.
• Low current consumption: Designed for low current consumption, making it suitable for battery-powered applications.
• High sensitivity: Provides high sensitivity for receiving weak FM signals.
• Low distortion: Offers low distortion for high-quality audio reproduction.

Benefits:

• Simplified circuit design: Integrates all necessary functions, simplifying circuit design and reducing the number of external components required.
• Low power consumption: Low current consumption extends battery life in portable applications.
• Improved performance: High sensitivity and low distortion provide excellent audio quality.
• Reduced cost: Integrated design reduces the overall cost of the solution.
• Stable and reliable operation: PLL frequency synthesizer ensures stable and reliable operation.

Additional Details:

The U2100B typically requires a minimum number of external components, such as a loop filter for the PLL and decoupling capacitors. The operating frequency range is determined by the external components used in the PLL frequency synthesizer. Design considerations include proper grounding and shielding to minimize interference. Consult the Atmel datasheet for detailed specifications on operating voltage, current consumption, and recommended external component values.