RTC6711A

Introduction

The RTC6711A is a highly integrated 2.4 GHz wireless audio/video receiver IC launched by RichWave Technology Corporation (Taiwan). It is specifically designed for analog/digital wireless transmission in the 2.4 GHz ISM band (outside IEEE 802.11 standards). The chip integrates a full-link solution from RF front-end to baseband demodulation. It supports both FM (Frequency Modulation) and FSK (Frequency Shift Keying) demodulation modes, capable of processing analog audio/video signals or digital data. A complete wireless receiving system can be built with minimal external components.

Important Note: The RTC6711A operates in the 2.4 GHz band (same as Wi-Fi/Bluetooth), which is distinct from the RTC6715A/RTC6705A series (5.8 GHz). Pay attention to the frequency band difference during procurement and design to avoid interference.

Key Features

RF & Demodulation Performance

• Operating Frequency: 2.4 GHz ISM Band, typical frequency points include 2.414 GHz, 2.432 GHz, 2.450 GHz, 2.468 GHz (customizable via SPI).
• High Sensitivity: Typical receiving sensitivity is -87 dBm (higher in FSK mode), ensuring stable operation in weak signal environments.
• Dual-Mode Demodulation: Supports Analog FM (for audio/video) and Digital FSK (for data transmission), offering flexible application scenarios.
• High Data Rate: In FSK mode, the data slicing bit rate can reach up to 4 Mbps (typical).

Integrated Functions

• Full-Link Integration: Built-in Low Noise Amplifier (LNA), Mixer, IF Amplifier, FM/FSK Demodulator, Automatic Gain Control (AGC), and FSK Data Slicer.
• Signal Strength Indication: Provides RSSI (Received Signal Strength Indicator) voltage output for real-time signal quality monitoring or implementing "mute on signal loss" functions.
• Channel Control:
  • Fixed Mode: 4 preset channels can be selected directly via 3 digital pins, eliminating the need for an external MCU in simple applications.
  • Programmable Mode: Receiving frequency and internal registers can be precisely configured via the SPI interface.
• Color Demodulation: Supports color demodulation for global mainstream TV standards (NTSC/PAL/SECAM).

Package & Reliability

• Package: 48-pin QFN (Quad Flat No-Lead) package (dimensions approx. 6.9mm x 8.4mm or 6.3mm x 8.4mm), lead-free pads, RoHS compliant.
• Supply Voltage: Supports a wide voltage range, typically 2.5V ~ 5.5V (some batches support 1V ~ 9V), compatible with both 3.3V and 5V systems.
• Operating Temperature: Industrial grade range, typically -40°C to +100°C (some datasheets specify up to +125°C).

Typical Specification Table

Typical Applications

• 2.4 GHz Wireless Surveillance Systems:
  • Wireless Cameras: Used as the receiver, paired with transmitters like RTC6701/RTC6502 for analog video transmission.
  • Home Security: Low-cost wireless doorbells and surveillance camera receiver modules.
• Consumer Electronics:
  • Baby Monitors: Transmitting audio and video from a baby's room.
  • Wireless Audio Devices: Wireless headphones, wireless speakers (requires a paired transmitter).
  • Toys & Remote Control: Figure transmission for 2.4GHz remote control cars and drones (entry-level or low-cost solutions).
• Industrial & IoT:
  • Wireless Data Acquisition: Used for sensor data transmission in FSK mode.
  • Smart Home: Receiving simple wireless control signals.
• Automotive Electronics: In-car wireless reverse camera receiver (2.4 GHz band).

Development & Design Notes

1. Band Interference: The 2.4 GHz band is a crowded ISM band (Wi-Fi, Bluetooth, ZigBee all operate here). When designing, select appropriate channels (e.g., 2.414/2.432/2.450/2.468 GHz) to avoid main Wi-Fi channels, or use frequency-hopping techniques.
2. Peripheral Circuits: Despite high integration, a precise 50Ω impedance matching network (inductor/capacitor combination) is required to connect the antenna, optimizing receiving sensitivity and suppressing harmonics. Refer to the reference design in the datasheet for details.
3. Antenna Design: A PCB onboard antenna or external rod antenna is recommended. The antenna layout should be kept away from digital signal lines (e.g., SPI, SDIO) and switching power supplies to minimize EMI/RFI interference.
4. Video Output: The chip directly outputs CVBS (Composite Video) signals (1Vp-p, 75Ω), which can be connected directly to a monitor or video capture card. For S-Video or Component output, an external decoder chip (e.g., ADV7280) is required.
5. Audio Output: Provides stereo audio output (after 6.0 MHz and 6.5 MHz subcarrier demodulation) with an amplitude of 2Vp-p. A capacitor is needed for DC blocking before connecting to an amplifier or headphones.
6. Pairing: The RTC6711A is typically used with RichWave transmitter chips (e.g., RTC6701, RTC6502, RTC6721) to ensure optimal compatibility and performance.
7. Version Differences: Note that the suffix "A" may indicate a version upgrade or minor package adjustment (e.g., size change from 6.9mm to 6.3mm). Verify the dimensions of the specific batch when designing the PCB.