January 27, 2011 - New Japan Radio Co., Ltd. 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.*1
*1 An additional power amplifier matching to the driven speaker size and type, is necessary.
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 inter-faceProviding reduction of development cost by built-in micro-controller less push-button inter-face
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.
- Cradle speaker for portable audio players and portable games Active speakers
- Operating Voltage: +2.7 to +5.5V
- Low current consumption: 2mA typ.(Active mode)
- Stand-by function: 1µA max.(stand-by mode)
- Pop-noise reduction
- semi-differential transmission input
- Pushbutton interface EVR: +6dB to -62dB, MUTE
- Adjustable initial Volume: -6dB, -10dB, -14dB, -18dB
- Attenuator/Soft MUTE Function: -10dB, -15dB, -20dB, MUTE
- Package outline: SSOP20-C3 (6.5×6.4×1.25mm typ.)
- Engineering Samples(ES): already available from November 2010
- Mass Production(MP): already available from January 2011