Infineon Technologies AG is extending its portfolio of energy-efficient lighting ICs with a new family of low-cost linear LED drivers. The new BCR320 and BCR420 product families address the burgeoning market for energy-saving and environmentally friendly light-emitting diode (LED) lighting solutions. Specifically designed for driving 0.5 W LEDs with a typical current of 150 to 200 mA, these LED drivers feature a negative thermal coefficient contributing to a long lifetime of LEDs and a digital interface for a pulse width modulation (PWM) signal for dimming.
With the recent introduction of higher efficiency 0.5 W LEDs, this class of products is expected to be adopted in a wider range of applications. However, currently available resistor solutions for biasing LED current have significant disadvantages such as inhomogeneous light output and reduced lifetime of LEDs. Alternatively, switch mode drivers do not meet the required price point for 0.5 W LED applications, and drive up the number of parts and the complexity of driver circuit.
The new BCR320 and BCR420 LED drivers are tailored to address these deficiencies for 0.5 W LED applications, providing a very low cost and simple solution with a small form factor. With both devices, the usage of inductors, capacitors and free-wheeling diode can be avoided resulting in cost savings and a very small PCB space requirement. The elimination of electrolytic capacitors can also contribute to the extended lifetime of the LED system.
The BCR320 products are designed for a peak output current of up to 300 mA. For continuous operation, a maximum nominal current of 250 mA is recommended. While this device has an internal breakdown voltage of typically 20 V, it can be operated at supply voltages of 24 V or higher since the driver is operated in series with the LEDs. The BCR320 is targeted at general lighting, architectural, and mood lighting applications. Another fast growing segment is shop lighting where 0.5 W LEDs are preferred in order to spread the light and avoid glare. BCR320 devices have a negative thermal coefficient, which means that in case of temperature increase the current is lowered with a slope of 0.2% / K. The BCR320U and BCR321U versions are available in a very small SC-74 package (2.9 x 2.5 x 1.1 mm) with 1 W power dissipation. The BCR320P and BCR321P types will be offered in a SOT-223 package (6.5 x 7.0 x 1.6 mm) providing a higher power dissipation of 2 W. The BCR321U and BCR321P versions both offer a logic level input for dimming.
The BCR420 products have a higher internal breakdown voltage and a lower output current than the BCR320 devices. The internal breakdown voltage is typically 50 V and the nominal output current is 150 mA. The BCR420 LED drivers are intended for use in similar applications as mentioned above for a maximum drive current of 150 mA. In addition, qualification for use in automotive applications, based on AECQ 101 certification, is ongoing. BCR420 and BCR421 products are available in SC-74 package. The BCR421 is the dimmable version with a microcontroller interface.
For more information, contact Infineon Technologies North American Corp., 640 N. McCarthy Blvd., Milpitas, CA 95035. Phone: 408-503-2791.