STMicroelectronics 5-channel (2 LEDs in series per channel) step-up white LED driver demonstration board based on the STLED25 STMicroelectr STEVAL-TLL013V1 Data Sheet

   

   

   

For further information contact your local STMicroelectronics sales office.

September 2011

Doc ID 022250 Rev 1

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5-channel (2 LEDs in series per channel) step-up white LED

driver demonstration board based on the STLED25

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Operating input voltage range from 2.3 V to 
5.5 V

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± 7.5% LED current accuracy

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Two LEDs in series per channel

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High-side current source

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Up to 125 mA of total LED current

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86% efficiency at 100 mA

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PWM dimming with automatic shutdown time 
window

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2.5 MHz switching frequency

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RoHS compliant

The STEVAL-TLL013V1 demonstration board 
was designed to demonstrate the performance of 
the STLED25, a fixed frequency, high-efficiency, 
boost DC-DC converter with five parallel high-side 
current sources.

The STLED25 is able to provide 125 mA of total 
current with a maximum voltage of 7.5 V on each 
channel.

Each current source supports single or dual LED 
connections. The output voltage of the step-up 
converter is automatically set at 100 mV above 
the highest voltage required on any driver to 
guarantee the proper operation of the linear 
current sources. The device implements a self-
test feature to detect any failure of the LEDs and 
to disable the related channel. 

The failure  status is reset as soon the IC is 
disabled. This mode of failure detection allows the 
device to continue operating driver channels that 
are operating normally, while avoiding excessive 
power consumption or associated thermal issues.