Products, Materials + Tools | Aug 13, 2013

Dialog Semiconductor LED Driver Delivers High Performance and Lower Costs in Commercial Lighting

Dialog Semiconductor plc, a provider of highly integrated power management, audio, AC/DC and short-range wireless technologies, today announced a new solid state lighting (SSL) LED driver that integrates boost and flyback converters into a single IC to reduce the bill of material (BOM) costs and simplify the design, compared to conventional two-stage driver approaches, while delivering exceptional performance. The new iW3623 was developed by Dialog’s Power Conversion Business Group, formerly iWatt Inc., acquired in July 2013 and delivering on Dialog’s product portfolio diversification strategy to expand into the digital power management market space.

iW3623 Key Features:
•    Output power: 3W to 45W
•    Universal input range: 100 – 277VAC
•    High power factor (PF) >0.95
•    Low total harmonic distortion (THD) <10%
•    Flickerless technology eliminates LED flicker with <5% 100Hz – 120Hz output current ripple
•    Integrated boost and flyback converters, PrimAccurate primary-side control: reduce solution size, lower BOM cost, increase reliability
•    NTC-based LED over-temperature protection (OTP) and derating
•    Meets global standards, including European Union IEC61000-3-2(1) requirement
•    Compatible with Zhaga(2) hot-plug LED module for LED light interchangeability

The iW3623 offers a universal 100VAC to 277VAC input range and output power up to 45W. It integrates a boost controller for power factor correction (PFC) and a flyback converter for LED current regulation, while enabling high PF >0.95 and low total harmonic distortion (THD) of <10%. Dialog’s patented Flickerless™ design achieves a near-zero 100 to 120Hz output ripple and the built-in over-temperature protection (OTP) and derating enables lighting designers to deliver a predictable, reliable bulb operating life.

The rich combination of integrated features makes the iW3623 an ideal solution for a wide range of non-dimmable, commercial SSL downlight, PAR, T8, and flat panel ceiling lamp applications.

The iW3623 provides additional BOM savings by using Dialog’s patented PrimAccurate™ primary-side control technology that eliminates the need for a secondary-side regulator and optical feedback isolator. It also allows FETs to be replaced with lower cost bipolar junction transistors (BJTs). While using BJT switches lowers the total solution cost, achieving high conversion efficiency can be a challenge. The iW3623 solves this by using quasi-resonant mode switching for both the boost and flyback stages and dynamic base current to optimise conversion efficiency and minimise EMI. Additionally, Dialog’s EZ-EMI® technology simplifies EMI filtering to further minimise the external component count.

Most power ICs are designed with a thermal shutdown feature, which simply shuts the IC down in high temperature environments. This protects the IC, but not the LED driver circuit. The iW3623 includes a robust, built-in over-temperature protection and derating function that actually monitors the temperature inside the sealed SSL bulb. The OTP feature is configured via an NTC resistor. When thermal conditions in the bulb reach the set temperature, the iW3623 automatically and incrementally reduces the current drive to the LEDs. This lowers the power dissipation, results in cooler operation, and ensures the temperature rating of the electrolytic capacitors in the system is not exceeded. Derating allows the capacitors to operate within the maximum lifetime of the SSL bulb and results in a predictable bulb operating life. The derating of the current drive results in negligible light reduction, so users will likely not experience any visible changes in light output. In extreme temperature situations, the iW3623 will shut down the current drive to the LEDs to prevent safety and fire risks.

Additional, iW3623 safety features include LED open/short circuit, single fault, over-current, current sense resistor short-circuit, input over-voltage, brown-out and AC line over-voltage/frequency protections. During output over-voltage conditions, the iW3623 goes into an extended discharge mode, while maintaining a quick recovery, allowing support for hot-plug LED modules without causing dangerously high output voltages.

Packaging, Pricing, Availability:
The iW3623 is available now in production quantities. It comes in a standard, 14-lead SOIC package and is priced at US $0.93 each in 1000-piece quantities.
Product brief is available:  iW3623 Product Brief.

PrimAccurate, Flickerless and EZ-EMI are registered trademarks of iWatt Inc., an affiliated company of Dialog Semiconductor plc. All other trademarks and registered trademarks are the property of their respective owners.
(1)  European Power Supply Manufacturers Association standard - IEC 61000-3-2:
(2)  The Zhaga Consortium:

About Dialog Semiconductor:

Dialog Semiconductor creates highly integrated, mixed-signal integrated circuits (ICs), optimised for personal portable, low energy short-range wireless, LED solid state lighting and automotive applications. The company provides flexible and dynamic support, world-class innovation and the assurance of dealing with an established business partner.
With its focus and expertise in energy-efficient system power management and a technology portfolio that also includes audio, short-range wireless, AC/DC power conversion and multi-touch, Dialog brings decades of experience to the rapid development of ICs for personal portable and digital consumers applications, including smartphones, tablets, Ultrabooks™ and digital cordless phones.
Dialog’s power management processor companion chips increase the performance of portable devices by extending battery lifetime, enabling faster charging and enhancing the consumer’s multimedia experience. With world-class manufacturing partners, Dialog operates a fabless business model.
Dialog Semiconductor plc is headquartered near Stuttgart with a global sales, R&D and marketing organisation. In 2012, it had $774 million in revenue and was one of the fastest growing European public semiconductor companies. It currently has approximately 1,000 employees worldwide. The company is listed on the Frankfurt (FWB: DLG) stock exchange (Regulated Market, Prime Standard, ISIN GB0059822006) and is a member of the German TecDax index.  It also has convertible bonds listed on the Euro MTF Market on the Luxemburg Stock Exchange (ISIN XS0757015606).