By Christoph Hammerschmidt
eeNews Europe Automotive
Inova Semiconductors now offers its LED driver & controller chip not only integrated into smart LED modules, but also as a standalone driver chip according to the Iseled Alliance specifications. The device enables the construction of customer-specific LED chains for ambient and functional lighting in vehicle interiors.
The INLC10AQ can be used to build customer-specific LED chains that can be controlled via a bidirectional differential two-wire bus. Thus, up to 4079 LED drivers and controllers can be interconnected in a single array via daisy chain. In addition, smart LED modules, which integrate drivers & controllers and RGB LEDs in one package, are also available from various manufacturers in volume quantities and with qualification for the automotive industry.
The Inova INLC10AQ offers functions such as color/brightness control and dimming of the lighting. It supports LED brightness calibration and color temperature compensation of red LEDs over the dominant wavelength. The built-in one-time programmable (OTP) memory stores calibration and compensation data values, eliminating the need for LED binning. During the development of the driver / controller chip, the oscillator was integrated, so no additional external components are required. The chip requires only a single supply voltage and also contains a built-in LDO (linear voltage regulator), a temperature sensor and comprehensive diagnostic functions.
LED chains can be daisy-chained to multiple INLC10AQ devices or other Iseled products via a differential bidirectional serial bus with 2 Mbps and CRC (Cyclic Redundancy Check). The chip contains three independent constant current sinks, each controlled by PWM (488 Hz, 12 bit). In a LED chain, each chip is individually addressable via the serial bus with a proprietary bus protocol.
 |
| Application example for chain with external RGB LEDs. |
The INLC10AQ can also be used as a converter in the periphery of the microcontroller. The device then converts the asymmetrical signal into a differential signal and establishes the connection with the first LED in the chain. As a converter, it can also be combined with other authenticated Iseled products that contain the INLC10AQ controller and RGB LEDs in a common package.
In addition to driving smart LEDs, the outputs to three LEDs with an integrated AD converter can be used to detect the voltage applied to the pins. This allows simple sensors (e.g. proximity, touch, pressure sensors) or adjustment knobs to be integrated into the LED chain. The data is then transferred back to the controller via the Iseled bus, eliminating the need for additional wiring of the sensors.
The INLC10AQ is a mixed-signal component in a 16-pin WETQFN package measuring only 3 mm × 3 mm × 0.9 mm. The operating temperature range is specified with –40 °C to +105 °C. In addition, the device is qualified according to the automotive industry test specifications AEC-Q100.
