IRPLCFL4 International Rectifier, IRPLCFL4 Datasheet - Page 4

• Manufacturer Part Number: IRPLCFL4
• Description: IC BALLAST DIMMING CFL 3-WAY
• Manufacturer: International Rectifier

Specifications of IRPLCFL4

• Main Purpose: Lighting, Ballast Control
• Utilized Ic / Part: IR2156
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Other names: *IRPLCFL4

IRPLCFL4
Functional Description
This solution adopts a completely different approach to the problem. Here we incorporate a voltage
doubler at the front end in all modes of operation giving a fixed 300VDC bus. Consequently by
choosing correctly the dead time and value of the snubber capacitor it is not difficult to achieve soft
switching in all modes of operation.
By simply changing the frequency between 3 defined settings, however, it was found to be extremely
difficult to set a point where the dim level is 50%. The problem with this is that the lamp current against
ballast frequency characteristic of the system exhibits a very sharp knee such that as the frequency
increases the lamp current is gradually reduced up to a point at which a small increase of frequency
will result in a very large reduction in the lamp current.
Ballast / Lamp Operating Characteristic
Lamp
Current
Ballast Running
Frequency
4
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