The iW3626 is a high performance single stage off-line LED driver using a proprietary hybrid control architecture, allowing high power factor correction (PFC) while minimizing LED current ripple. This proprietary hybrid control combines a high power factor architecture with a low LED ripple current architecture, and a circuit to modulate the two operating modes that is programmable by the user. This user programmability offers the flexibility to select the balance between PF and ripple current. The iW3626 has two pins that have two functions each, one that during start-up sets the PF and ripple current level and then provides the main current sensing function during steady state operation and a second that sets over temperature protection during start-up and then provides an input for the main feedback to the control circuit during steady-state operation. This allows extra functionality in the smallest package possible, as the iW3626 is available in the space and cost saving SOT-23-6 package.

Using iWatt's PrimAccurate™ technology, the iW3626 monitors the magnetic element, whether an isolated transformer or a power inductor, and uses those signals for the main feedback control, eliminating the need for expensive and fragile opto-isolators in isolated applications. The digital control circuit used in the iW3626 removes the need for external compensation, simplifying the design and further reducing the external component count. The iW3626 fully protects the end applicaiton with over temperature, over current and short circuit protection. The most important protection feature is the over temperature protection feature which derates the LED current when the temperature of the IC approaches its thermal shutdown threshold. The IC will step down the LED output current until achieving thermal equilibrium, maintaining some light output until the thermal event goes away, then the LED driver increases the output current again in equal steps until reaching the maximum programmed LED current output.

The iW3626 is available in three options, depending upon the output voltage and current needed for the end application. See the application and ordering information sections of the datasheet for more information.

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