Products, Materials + Tools | Dec 02, 2014

Taiwan Semiconductor LED Drivers Deliver Constant LED Currents up to 2 A and up to 91% Efficiency

With their TS193x, TS194x and TS197x LED constant current drivers, Taiwan Semiconductor is introducing high-efficiency, buck-boost-converter based solutions for the control of white LEDs. The TS19371CX6 step-up converter/driver (boost) for white LEDs meets all the demands placed on a modern switching-regulator-based LED driver

•    Operation with low supply voltage (9V to 15V)
•    Fast switching frequency (1.2MHz)
•    High efficiency (up to 89%)
•    Extremely stable, adjustable LED operating current (up to 350mA)
•    Flexibility (various LED configurations can be operated)
•    Dimmability (0% to 100%, 3 options)

With supply voltage of 15V, for example, the TS19371CX6 can drive 126 LEDs in 14 parallel-switched strings of 9 LEDs, each with 20mA and efficiency of almost 89%, and also just a single LED string consisting of six white 1W HP LEDs with 350mA (efficiency 88%). The required LED operating current is established using a very small feedback resistor (e.g. 0.22 Ohm for 350mA) in the LED chain, ensuring that power dissipation from resistance is kept to a minimum. For operation, the TS19371CX6 only requires four external components (two capacitors, one choke and one diode).

The TS19377CS is a high-efficiency buck converter , able to supply switch output current of 2A at 91% efficiency and switching frequency of 330kHz, while the TS19451CY is an LED driver IC that ensures efficient, precise current limiting and current setting for LED strings operating on mains voltage. Housed in the small SOT89 package, the TS19451 can be operated directly on 230V mains power using either an upstream bridge rectifier with a smoothing capacitor, or directly connected to a DC source up to 400V to drive long LED strings with well over 200V total forward voltage. The only additional external components required for the LED control are one diode, two further capacitors and a choke. And integrated 475V power MOSFET drives the LED chain so that the operational current of the chain amounts to a constant 50mA (fixed internal preset), independent of voltage fluctuations.

Detailed information about this LED drivers as well as other TS LED driver ICs can be found at

About TSC:
Taiwan Semiconductor was established in 1979 and remains under the direction of its founder and CEO, Arthur Wang. The company has grown from its beginnings as a local manufacturer, to a global enterprise with 2,000 employees, and achieving 2013 revenue of US $170 million. Taiwan Semiconductor is publicly traded on the Stock Exchange Corporation of Taiwan.  
Recognized for more than 35 years for its core competence in discrete Power Rectifiers, Taiwan Semiconductor has expanded its product portfolio to include Analog ICs, Power Transistors and MOSFETs,  and now provides a complete solution from one source.
Taiwan Semiconductor’s production facilities in China and Taiwan are fully compliant to current automotive and environmental standards such as TS16949, ISO9001 and ISO14001.  Thirteen worldwide sales offices are located to conveniently serve customers throughout Asia, Europe, and America.
Taiwan Semiconductor products are used in a vast array of applications in the electronics industry, including automotive, computer, consumer, industrial, telecom and photovoltaic. Through strategic expansion of innovative manufacturing capabilities, and its focus on pioneering efficient semiconductor solutions, Taiwan Semiconductor is committed to being the right choice for a successful and lasting business relationship.