1. Introduction
The JL Chip AC6925A is a high-performance stereo lossless sound quality Bluetooth audio chip designed for a wide range of audio applications. It integrates Bluetooth 5.0 dual-mode connectivity, supports various audio decoding formats, and offers features like FM radio, TWS pairing, and multiple input/output options. This manual provides essential information for understanding, setting up, and operating your AC6925A chip.
Note: The standard program version of the AC6925A chip has been discontinued. For new designs or improved performance and lower power consumption, consider using the new generation AC6955F chip, especially if only Bluetooth functionality is required.
2. Specifications
2.1 Core Features
- CPU: High performance 32-bit RISC CPU, DC-160MHz operation, Support DSP instructions, 6-Vectored interrupts, 4 Levels interrupt priority.
- Bluetooth Protocol: V5.0+BR+EDR+BLE compliant, supports Piconet and Scatternet.
- Audio Decoding Formats: MP3, WMA, WAV, APE, FLAC, F1A, NWT, AMR, M4A, DTS.
- Lossless Formats: WAV, APE, FLAC.
- Supported Bluetooth Profiles: a2dp, avctp, avdtp, avrcp, hfp, spp, smp, att, gap, gatt, rfcomm, sdp, l2cap.
2.2 Flexible I/O
- 11 GPIO pins, individually programmable as input or output.
- Internal pull-up/pull-down selectable for all GPIO pins.
- CMOS/TTL level Schmitt triggered input.
- External wake up/interrupt on all GPIOs.
2.3 Peripheral Features
- One full speed USB 2.0 OTG controller.
- One audio interface supporting IIS, left/right adjusted, and DSP mode.
- Four multi-function 16-bit timers (capture and PWM mode).
- Three 16-bit PWM generators for motor driving.
- One 16-bit active parallel port.
- One full-duplex basic UART, one full-duplex advanced UART.
- One SPI interface (host and device mode).
- Two SD/Card Host controllers.
- One IIC interface (host and device mode).
- One Quadrate decoder, Watchdog.
- 1 Crystal Oscillator.
- 16-bit Stereo DAC with headphone amplifier (SNR >= 95dB).
- 1 channel ADC (SNR >= 90dB), 1 channel PGA amplifier.
- 2-channel Stereo analog MUX.
- 8 channels 10-bit ADC, 2 channels 8 levels Low Voltage Detector.
- Power-on reset.
- Embedded PMU support low power mode.
2.4 FM Tuner
- Support worldwide frequency band 76-108MHz.
- Fully integrated digital low-IF tuner & frequency synthesizer.
- Autonomous search tuning.
- Digital auto gain control (AGC).
- Digital adaptive noise cancellation.
- Programmable de-emphasis (50/75 us).
- Receive signal strength indicator (RSSI).
- Radio search in multi-channel simultaneously.
- Digital volume control.
2.5 Power Supply & Temperature
- VBAT: 2.2V to 5.5V
- VDDIO: 2.2V to 3.6V
- RTCVDD: 2.2V to 3.6V
- Operating Temperature: -20°C to +70°C
- Storage Temperature: -65°C to +150°C
3. Setup
3.1 Pin Definition
The AC6925A chip is available in a QSOP24 package. Refer to the diagram below for the pin assignments to ensure correct integration into your circuit design.
3.2 Schematic Diagram
For detailed circuit design and implementation, a standard schematic diagram is available. This chip can be programmed to correspond to these standard schematic diagrams.
Schematic Download Link: https://pan.baidu.com/s/1XtV8fQRmTtn91DnsxYmqWA
Extraction Code: rto8
3.3 Recommended Components
The XPT9971 power amplifier is commonly used in conjunction with this chip in standard schematic diagrams. Ensure compatibility and proper integration with other components in your audio system.
4. Operating Instructions
The AC6925A chip supports various operating modes and functionalities, making it suitable for stereo Bluetooth speaker solutions with FM radio and plug-in card capabilities.
- Bluetooth Connectivity: Supports Bluetooth 5.0 dual-mode, BLE, and APP control. It also features Bluetooth TWS (True Wireless Stereo) for pairing two devices.
- Audio Playback: Decodes a wide range of audio formats including WAV, APE, FLAC (lossless), MP3, WMA, F1A, NWT, AMR, M4A, DTS. Playback can be initiated via SD/TF card or USB input.
- FM Radio: Utilize the integrated FM tuner to receive radio broadcasts within the 76-108MHz frequency band. Features include autonomous search tuning and digital volume control.
- Audio Input/Output: Supports MIC input for recording or voice applications, and AUX input for external audio sources. Provides stereo audio output.
- Special Functions: Includes recording capabilities, reverberation effects, and Bluetooth transmission functionality.
5. Maintenance
To ensure the longevity and optimal performance of your AC6925A chip, follow these general maintenance guidelines:
- Handling: Always handle the chip with care, preferably using anti-static precautions, to prevent damage from electrostatic discharge.
- Storage: Store the chip in a dry, cool environment within the specified storage temperature range (-65°C to +150°C).
- Cleaning: If necessary, gently clean the chip and surrounding components with a soft, dry brush or compressed air. Avoid using liquids or abrasive materials.
- Environmental Conditions: Operate the chip within the specified operating temperature range (-20°C to +70°C) and avoid exposure to excessive moisture or corrosive environments.
6. Troubleshooting
If you encounter issues with your AC6925A chip, consider the following:
- No Power: Verify that the power supply (VBAT, VDDIO, RTCVDD) is within the specified voltage ranges (2.2V-5.5V for VBAT, 2.2V-3.6V for VDDIO/RTCVDD) and correctly connected.
- Bluetooth Connectivity Issues: Ensure the chip is properly initialized and configured for Bluetooth operation. Check for interference from other wireless devices.
- Audio Playback Problems: Confirm that the audio files are in supported formats and that the storage media (SD/TF card, USB) is correctly inserted and formatted.
- FM Radio Reception: Check antenna connection and ensure you are within a good signal reception area.
- Chip Functionality: If experiencing general issues, ensure the correct program has been burned onto the chip according to the standard schematic diagrams.
- Upgrade Consideration: As mentioned, the standard program version of AC6925A is discontinued. If you are developing a new product or require only Bluetooth functionality, consider using the AC6955F chip for better performance and support.
7. User Tips
- Development Environment: When developing with the AC6925A, always refer to the latest datasheet and development kits provided by JL Chip for the most accurate information and tools.
- Power Management: Utilize the embedded PMU (Power Management Unit) and low power modes to optimize battery life in portable applications.
- GPIO Configuration: Take advantage of the flexible GPIO pins by programming them individually to suit your specific application needs for inputs, outputs, or interrupts.
- Audio Quality: For optimal audio quality, ensure proper grounding and shielding in your circuit design to minimize noise and interference.
8. Support
For further technical assistance, detailed datasheets, or inquiries regarding the AC6925A or AC6955F chips, please contact your supplier or the manufacturer directly. Always refer to official documentation for the most up-to-date information.
