LEDs and drivers for automotive display backlighting

According to ROHM, the devices address the need for increased functionality of clusters, car audio and navigation, climate control, switches and lcd/tft backlighting. The SMLZ1xx, SMLKxx,SMLVxx and SMLXAxx led family are available in range of top and side view package types, forward currents as well as luminous intensity (mcd). The emitted colours are cold white and warm white. Additionally, the leds offer high heat radiation for operation at high temperature, maintenance of high power at high currents and what ROHM describes as 'superior device reliability and durability'. With the development of its new BD81A04 LED driver series, ROHM says it is able to provide a complete design solution for display backlighting. The new IC is a four channel 120mA/ch led driver with an integrated buck boost dc/dc constant current driver which can be used to drive various leds for backlighting of displays or head up displays. Due to its topology it only requires one coil for buck boost configuration and is said to provide stable operation over a wide voltage range. The BD81A04 integrates mosfets like the PWM current driver or the boost FET. The advanced brightness control /dimming functions and the flexibility to combine fewer channels with higher output current round up the features of this device. For example, instead of using four channels with 120mA, it's now possible to achieve 240mA via two channels. Protection functions such as monitoring voltage, current, temperature and short circuit detection are also implemented. LED SMLx family samples and volume production are currently available, as are samples of the BD81A04 led driver with volume production starting in Q2 2012.