RTC6715A

Introduction

The RTC6715A is a highly integrated 5.8 GHz FM Receiver IC designed by RichWave Technology Corporation. It is specifically engineered for FM demodulation applications in the 5.8 GHz ISM band, making it an ideal companion chip for the RTC6705 transmitter. This single-chip solution integrates a Low Noise Amplifier (LNA), mixer, IF amplifier, FM demodulator, AGC, and audio processing units, requiring minimal external components. It is widely used in wireless audio/video transmission systems, offering high sensitivity and excellent signal stability.

Key Features

RF & Demodulation Performance

• Operating Frequency: 5.725 GHz ~ 5.875 GHz (covers the full 5.8 GHz ISM band).
• High Sensitivity: Typical sensitivity reaches -85 dBm, ensuring reliable signal reception even in weak signal environments.
• FM Demodulation: Dedicated FM demodulator for restoring analog video and stereo audio signals modulated by the RTC6705.
• Dual Audio Subcarriers: Built-in demodulators for 6.0 MHz and 6.5 MHz subcarriers, supporting both stereo and mono audio output.
• Signal Quality: High Signal-to-Noise Ratio (SNR) and low distortion ensure high-fidelity audio and clear video.

Integrated Functions

• Front-End Integration: Includes LNA, Mixer, and IF Amplifier to minimize external RF components.
• AGC (Automatic Gain Control): Built-in AGC adjusts the gain dynamically to maintain a stable output level across varying input signal strengths.
• RSSI Output: Provides a Received Signal Strength Indicator (RSSI) voltage output for real-time signal monitoring and network optimization.
• Noise Squelch: Hard mute function via noise squelch to eliminate background noise when no valid signal is present.
• Frequency Control: Operating frequency can be set via SPI interface or selected through 6 dedicated digital pins (24 fixed channels), eliminating the need for an external MCU in simple applications.

Package & Reliability

• Process: Advanced CMOS single-chip technology with integrated VCO and PLL.
• Package: 48-pin QFN (Quad Flat No-Lead), lead-free and RoHS compliant.
• Power Supply: 3.3V single power supply with low power consumption.
• Working Temperature: Industrial grade, typically -40°C to +85°C.

Typical Specification Table

Typical Applications

• 5.8 GHz Analog Video Transmission Systems:
  • Wireless Security: Wireless CCTV cameras, home security systems (receiver end).
  • Consumer Electronics: Baby monitors, wireless doorbells, wireless headphones (receiver end).
  • Drones (FPV): Analog FPV video receivers for drones and RC models.
  • Automotive: Car wireless reverse cameras, in-car entertainment wireless receivers.
  • Industrial: Wireless video surveillance backhaul, industrial field data acquisition.
• Audio Systems: High-quality wireless stereo audio receivers for speakers or headsets.

Development & Design Notes

1. Antenna Design: Use a 50-ohm impedance PCB antenna or external rod antenna. Keep the antenna trace away from digital lines and power supplies to minimize interference.
2. Shielding: Due to the high frequency (5.8 GHz), it is recommended to use a metal shield (can) over the PCB area to prevent EMI/RFI interference and ensure compliance with FCC/CE regulations.
3. Peripheral Matching: Although highly integrated, a small number of external passive components (inductors, capacitors) are required for the RF input matching network and IF filter to optimize performance. Refer to the reference design in the datasheet.
4. Channel Setting:
   • Fixed Mode: Use the 6 digital pins to select one of 24 pre-set channels (no MCU needed).
   • Programmable Mode: Use SPI to fine-tune the frequency and configure internal registers via a microcontroller.
5. Audio Output: The chip provides separate pins for audio demodulation. Ensure proper decoupling capacitors are placed on the audio output lines to filter DC offset and noise.
6. Pairing: The RTC6715A is designed to work with the RTC6705A transmitter. When designing a system, ensure both chips are configured to the same channel or frequency for successful communication.