Products, Materials + Tools | Dec 22, 2014

ISSI Introduces Cost-Cutting 4-Channel High Brightness LED Driver

ISSI introduces the IS31LT3117, an industry unique, four channel linear driver for high brightness LEDs. With an operating voltage range of 6 V to 53 V it can sink up to 350 mA per channel. If a higher current is required, the four outputs can be connected in parallel for a whopping 1.4 amps (4 x 350 mA) of combined current.

Operating at such high currents presents thermal challenges which are addressed in the IS31LT3117. First it is packaged in a thermally enhanced 16pin TSSOP to mechanically disperse heat to the PCB. Then it integrates thermal protection features and supports external transistors to offload any excess heat away from the device and unto the transistors.

The IS31LT3117’s silicon junction temperature is constantly monitored to keep it below 160°C and shuts down should this threshold be exceeded. However, to avoid a complete shutdown, the output current is reduced at a rate of 2.22%/°C when the junction temperature increases beyond 130°C. Should the die temperature continue to rise and exceed 160°C then the device will automatically shut down with no current to the LEDs.

Linear drivers are a simple and cost effective solution for driving LEDs; if their heat generation is properly managed. The IS31LT3117 is the right LED driver solution for high brightness LED lighting applications since it provides all the benefits of a linear driver while addressing the thermal issues.

With the new IS31LT3117 high cost savings are possible i.e. running at 48 VDC. Compared with single channel 24 V solutions the component count could be reduced from more than 25 components to a handful.

More information could be found at the ISSI website or

About ISSI:
Integrated Silicon Solutions is a leading Fabless semiconductor company that designs DRAM, Asynchronous SRAM/High Speed Memory(QUAD, Synch SRAM, RLDRAM 2/3), Flash, Analog and Mixed-Signal products.The typical customers could be found in the fields of Automotive, Communications, Industrial, Medical, Lighting, Military, and Digital Consumer/PC Peripherals. Customers appreciates the high quality (lot of products automotive qualified), broad portfolio and Long Term Support.  Headquartered in Silicon Valley, CA, ISSI was found in 1988 and went public in 1995 (Nasdaq: ISSI) .
More information about ISSI could be found at