Combined LED and front-panel driver targets home appliances

Vanessa Knivett

Analog Designline Europe (06/29/2009 12:28 PM ET)

austriamicrosystems has added the AS1115 to its LED driver portfolio, which combines display driving and key scanning functionality to provide a simple front panel solution. This eliminates the need for a separate microprocessor to provide the front panel display, making the AS1115 well-suited to seven-segment or dot matrix user interface displays for set-top boxes, VCRs, DVD players, washing machines, microwave ovens and other white good or personal electronic applications.

The AS1115 drives either eight 7-segment digits or 64 individual LEDs with 47mA per digit or 5mA per LED. LED brightness can be controlled by either analog or digital means. An external resistor can be used to adjust the current. Meanwhile, the 4bit PWM on each digit provides separate dimming capability, or developers can use global digital brightness control. And with an accuracy of 3% claimed, this part can be used to minimise intensity variations between the LEDs and LED modules, and therefore improve display quality.

A differentiating feature of the AS1115, according to austriamicrosystems, is built-in LED error detection. This detects open- or short-circuits within the multiplexed 8 x 8 LED array and provides an error report that identifies the location of the broken LED - helpful during production test.

The AS1115 operates from a single 2.7V to 5.5V supply, requiring 0.6mA of current during operation and 200nA in shutdown mode. Suitable for operating environments ranging from -40 to +85°C, this part comes in a 24pin QSOP package, or a TQFN package for space-constrained applications.

For more information on this, visit a href= "http://www.austriamicrosystems.com/LED-Driver/AS1115" target="_new" >austriamicrosystems' website