ON Semiconductor Implements Self Bias Transistor Technology for New Constant Current Regulators

Sep 23, 2011 ON Semiconductor, a premier supplier of high performance silicon solutions for energy efficient electronics, has expanded its portfolio of Constant Current Regulators (CCRs) to include the NSI50350A. This simple and extremely robust device is designed to provide a thermally efficient and cost-effective alternative to passive/discrete components or driver integrated circuit (IC) solutions for current regulation of Light Emitting Diodes (LEDs). The device is ideal for a variety of 1 watt (W) lighting applications including automotive, architectural lighting and signage.

The NSI50350A CCR incorporates Self-Biased Transistor (SBT) technology and regulates current over a wide voltage range. It is designed with a built-in LED driver and has a negative temperature coefficient to protect LEDs from thermal runaway at extreme voltages and currents. The 350 milliamp (mA) ± 10% steady state regulation current (Ireg) is ideal for driving 1.0 W LEDs; for applications requiring 2.0 W LEDs, two of the NSI50350A CCRs can be placed in parallel. The device has an operating temperature range of -55 deg C to +175 deg C.

The NSI50350A requires no external components allowing it to be designed as either a high or low-side regulator. The high anode-cathode voltage (Vak) rating of 50 volts (V) maximum enables the device to withstand voltage surges that are common in automotive, industrial and commercial signage applications. The device turns on immediately and is at 20 percent of full regulation with only 0.5 Vak applied.

"The popularity of solid state lighting continues to grow across many markets including automotive, architectural lighting and signage," said Dan Huettl, general manager and director of ON Semiconductor's Small Signal Division. "Ensuring that LEDs are not vulnerable to damage due to the challenging conditions in which they are used is crucial to their prolonged operation. The compact new NSI50350A from ON Semiconductor provides a dependable and easy-to-implement single component solution that offers engineers a highly effective way of ensuring LED protection in their applications."

The NSI50350A is offered in both DPAK-4 (NSI50350AD) or SMC (NSI50350AS) industry standard packages and are capable of dissipating 11 W and 5.8 W respectively.
Both devices are qualified to automotive AECQ-101 standard and are UL940-V0 certified. The the NSI50350AD is priced at $0.16 per unit and the NSI50350AS is priced at $0.12 per unit in 10,000 unit quantities.

Source: http://www.marketwatch.com/story/on-semiconductor-expands-portfolio-of-constant-current-regulators-for-10-watt-led-lighting-applications-2011-09-22
Author:  Alice Jones