40WLEDBULBGEVB: Dimmable 120 Vac, 6.5 W Input
Parallel-to-Series Lighting Circuit Evaluation Board
The 40WLEDBULBGEVB showcases an
enhanced parallel-to-series LED lighting circuit. It
uses updated control circuitry that allows the
ability to accommodate multiple LED voltages by
simply adjusting a single resistor (R3) as well as
compensating for drift in LED voltage with temperature. It also has superb PF, THD
performance, dimmability, and efficiency at a low cost.
ON Semiconductor’s parallel-to-series topology dynamically adjusts LED load voltage as the
instantaneous bridge output voltage varies. While a switch-mode power supply (a buck
converter) reconfigures the input voltage to match the load, this circuit reconfigures the load to
match the input voltage. When the instantaneous input voltage is relatively low, the LEDs are
configured in parallel. When the instantaneous input voltage is relatively high, the LEDs are
configured in series.
The circuit is designed for input voltages between 100 Vac and 140 Vac. ON Semiconductor
CCRs are used to provide constant LED current and to protect LEDs from over-voltage
conditions. The circuit employs an additional CCR (shown as CCR2) to increase LED current at
high voltages for improved PF and THD performance.
Evaluation/Development Tool Information
Product Status Compliance Short Description Parts Used
40WLEDBULBGEVB Active
Pb-free
Dimmable 120 Vac, 6.5 W Input Parallel-to-Series
Lighting Circuit Evaluation Board
NSIC2020JBT3G , NSIC2030JBT3G
http://www.onsemi.com/PowerSolutions/evalBoard.do?id=40WLEDBULBGEVB 5‐11‐17
