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Mainz, Germany, February
11, 2004
An application specific 40-channel LED display driver has been
developed by PREMA Semiconductor for the use in household
appliances. Each of the 40 output stages can sink a current of up to
100 mA. The status of the current steered outputs is controlled by a
micro controller via a serial interface and can be stored by a
40-bit latch.
The output current and thus the brightness of the LEDs can be
adjusted by an external resistor or an D/A converter. The integrated
power-on-reset provides a reset signal to the chip, if the supply
voltage drops below a certain value. A 'blank' input can be used to
switch off all output stages simultaneously. The high output voltage
range of up to 15 V allows the serial connection of multiple LEDs
per channel in order to achieve a higher light intensity.
The ASIC can be used as a LED driver for dot matrix displays as well
as for LED segments. The custom application consists of 16 5x5 dot
matrix modules, arranged in two lines. Two ASICs are used to control
the modules, one drives the 40 columns of the matrix, the other
delivers the base current for the PNP transistors, that multiplex
the 10 rows.
Both ASICs and the transistors can be mounted on the backside of the
LED display in a space saving way. Originally the ASIC has been
developed for household appliances, but it can also be used for
automotive applications as well as for information display systems.
Many customers decide to develop an ASIC instead of using a standard
LED driver: In addition to the technical advantages, which a custom
specific IC has over a standard solution, an ASIC guarantees a long
time availability.
The ASIC can be used very flexible for different types of display
matrices allowing a high degree of freedom for the product design.
An additional advantage is the protection against product piracy.
PREMA will participate and exhibit at the embedded world
(February 17-19, 2004 in Nuremberg, hall 12.0, stand 284), where the
customers can discuss ways to integrate their circuit into an ASIC
with our application engineers.
Please find more information on the PREMA web side: www.prema.com.
or www.prema.com/Application/led_driver.html
Contact:
Matthias Linde, PREMA Semiconductor GmbH
Phone: +49-6131-5062-167
prema@prema.com |
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