The IS1690 multi-speaker stereo audio chip is a compact, highly integrated, CMOS single-chip RF and baseband IC for Bluetooth v3.0 +EDR 2.4GHz applications. This chip is fully compliant with Bluetooth specifications and completely backward-compatible with Bluetooth 2.0 or 1.2 systems. It incorporates Bluetooth 1M/2M/3Mbps RF, single-cycle 8bit MCU, TX/RX modem, 5-port memory controller, task/hopping controller, UART interface, and ISSC’s own Bluetooth software stack to achieve the required BT v3.0 with EDR functions.
For superior audio and voice quality, it also integrates a DSP co-processor, a PLL, and a CODEC dedicated for voice and audio applications. For voice, it supports not only basic CVSD encoding and decoding but also enhanced noise reduction and echo cancellation are implemented by the built-in DSP to achieve better quality in both sending and receiving sides. For the enhanced audio applications, SBC decoding functions can also be carried out by DSP to satisfy Bluetooth A2DP requirements.
- Compliant with Bluetooth Specification v.3.0 + EDR in 2.4 GHz ISM band
- Supports the following profiles:
- Hands Free 1.5
- Headset 1.0
- A2DP 1.0
- AVRCP 1.0
- 16MHz main clock input
- Built-in internal ROM for program memory
- Supports connection to two hosts (phones, tablets, etc.) with HFP or A2DP profiles simultaneously
- Adaptive Frequency Hopping (AFH) avoids occupied RF channels
- Fast Connection supported
- Supports A-Law or µ-Law PCM format, or CVSD (Continuous Variable Slope Delta Modulation) for SCO channel operation
- Noise suppression
- Echo suppression
- SBC decoding
- Packet loss concealment
- Built-in one language (English) voice prompts and 20 events for each one
- 16 bit DAC and 16 bit ADC codec
- 94dB SNR DAC playback
- 85 dB SNR ADC.
Flexible HCI interface
- Built-in Lithium-ion battery charger (up to 350mA)
- Integrated 3V, 1.8V configurable switching regulator and LDO
- Built-in ADC for battery monitor and voltage sense.
- A line-in port for external audio input
- Two LED drivers
- High speed HCI-UART (Universal Asynchronous
- Receiver Transmitter) interface (up to 921600bps)