Providing cost reduction of cradle speaker with Micro-controller-less solution
New Japan Radio has introduced to the market, the NJU7394, Push-button Interface Electronic Volume suitable for portable audio device’s cradle speakers.
Background of development
Cradle speaker needs push-button for volume control, so it needs control system with micro-controller that increases parts cost and development man-hour.
To clear up theses problems, New Japan Radio Co., Ltd. has developed the NJU7394 push-button interface electronic volume suitable for cradle speaker system and providing simple, easy circuit design and reduction of parts.
Features
The NJU7394 consists of semi-differential input electronic volume with variable gain range from +6dB to –62dB and MUTE, attenuator, push-button interface logic circuit and the power control logic circuit in one-chip.
Providing reduction of development cost by built-in micro-controller less push-button interface
- The NJU7394 has built-in push-button interface for volume UP/DOWN control and power ON/OFF making application possible without the use of micro-controller. It provides cost reduction of development, because of software less.
Semi-differential input provides reduction of ground loop noise effects
- The NJU7394 has semi-differential transmission input (three wire: L, R, and COMMON (GND))/ The transmission reduces the ground loop noise occurred between equipments connected each other. It provides high quality sound
Setting the initial value of volume and attenuation by circuit constant, provides easy spec charge model by model
- The NJU7394 can change the initial value of volume, attenuation and function by the constant of external components. It makes spec change by model and destination easy, so it provides shortening product development term and cost reduction.
Application
- Cradle speaker for portable audio players and portable games
- Active speakers
NJU7394 Block Diagram
