Volume 2 Click is a compact add-on board that provides the user with complete digital volume control. This board features the NJU72341, a 2-channel I2C configurable electronic volume IC with external mute control from NJRC. It controls two independent low distortion audio channels with a vast volume control range from 0 to 95dB with 1dB step offering zero-cross detection to protect pop noise. It operates with a simple I2C serial interface that accepts 8-bit data offering low distortion and noise. This Click board™ is suitable for stereo and multi-channel audio systems and represents a perfect solution for remote audio volume control applications.

Volume 2 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Volume 2 Click as its foundation uses the NJU72341, a 2-channel I2C configurable electronic volume IC with an external mute control from NJRC. The NJU72341 operates as an audio signal processor with many characteristics useful in an audio application, such as low noise typical of 2.0µVrms and low distortion of 0.002%. It controls two independent audio channels with a vast volume control range from 0 to 95dB with 1dB step offering zero-cross detection to protect pop noise. That's why this Click board™ is suitable for stereo and multi-channel audio systems.

The NJU72341 has to receive a specific supply voltage to operate appropriately, in this case, 12V. Unlike the Volume Click, which has symmetrical power supply, in this case, we have only one positive power supply. Bringing just a positive power supply, the noise generated by that power supply will transmit to the output, representing a side effect. For this purpose, Volume 2 Click employs a boost converter unit made by combining MIC5235 and MIC2606, both from Microchip. MIC5235 provides 13V out of 5V from the mikroBUS™ power rail, which then the MIC2606, with a feature of massive noise suppression, lowers it to 12V and then supplies NJU72341 reducing the noise generated at its output.

Volume 2 Click communicates with MCU using standard I2C 2-Wire interface, with a clock frequency up to 100kHz in the Standard and 400kHz in the Fast Mode. Also, the user has the option of external mute control configurable through the PWM pin of the mikroBUS™ socket labeled as MTE.

This Click board™ operates only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

• Interface: I²C
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 5V
• Volume Control Range: Min. 0dB, Max. 95dB
• Step Size: 1db
• Programmable Gain: Min. 4db, Typ. 6db, Max. 8db
• Total Harmonic Distortion: Typ. 0.002%, Max. 0.01%
• Operating Temperature Range: -40°C, Typ. +25°C, Max. +85°C

• Schematic
• MIC2606 Datasheet
• MIC5235 Datasheet
• NJU72341 Datasheet
• mikroSDK
• LibStock