The IS2025 stereo audio chip is a compact, highly integrated, CMOS single-chip RF and baseband IC for Bluetooth v4.1 + EDR 2.4GHz applications. This chip is fully compliant with Bluetooth specifications and is completely backward-compatible with Bluetooth 3.0, 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 Microchip’s own Bluetooth software stack to achieve the required BT v4.1 with EDR functions.
For delivering 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, 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/AAC_LC decoding functions can be also carried out by DSP to satisfy Bluetooth A2DP requirements.
In addition, to minimize the external components required for portable devices, a battery voltage sensor, battery charger, a switching regulator and LDO are integrated to reduce system BOM cost for various Bluetooth applications. As the market of portable/wireless speakers demand is increasing, a stereo 2 channels 2.3W class-D amplifier which provides up to 100dB SNR is also built-in to reduce BOM cost and PCB area.

Additional Features

System Specification
• Compliant with Bluetooth Specification v.4.1 (EDR) in 2.4 GHz ISM band
• Supports the following profiles:
• HFP 1.6
• HSP 1.1
• A2DP 1.2
• AVRCP 1.5
• SPP 1.0
• PBAP 1.0
Baseband Hardware
• 16MHz main clock input
• Built-in internal ROM for program memory
• Support to connect to two hosts ( phones, tablets…) with HFP or A2DP profiles simultaneously
• Adaptive Frequency Hopping (AFH) avoids occupied RF channels
• Fast Connection supported
RF Hardware
• Fully-certified Bluetooth 4.1 (EDR) system in 2.4 GHz ISM band
• Combined TX/RX RF terminal simplifies external matching and reduces external antenna switches
• Max. +4dBm output power with 20 dB level control from register control
• Built-in T/R switch for Class 2/3 application
• To avoid temperature variation, temperature sensor with temperature calibration is utilized into bias current and gain control
• Fully integrated synthesizer has been created. There requires no external VCO, varactor diode, resonator and loop filter
• Crystal oscillation with built-in digital trimming for temperature/process variations
Audio processor
• Noise suppression
• Echo suppression
• SBC and optional AAC decoding
• Packet loss concealment
• Built-in four languages (Chinese/ English/ Spanish/ French) voice prompts and 20 events for each one
Audio Codec
• 20 bit DAC and 16 bit ADC codec
• 98dB SNR DAC playback
• Built-in 2 channel 2.3W class-D amplifier for a 4Ω speaker
Peripherals
• Built-in Lithium-ion battery charger (up to 350mA)
• Integrate 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
Flexible HCI interface
• High speed HCI-UART (Universal Asynchronous Receiver Transmitter) interface (up to 921600bps)
Package
• 8 x 8 mm2 68QFN package