IRPLCFL4 International Rectifier, IRPLCFL4 Datasheet - Page 2

• 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

The 3 way dimming light bulb has two filaments inside which produce different light outputs when
connected to the AC line. These filaments are connected in series such that the mid point goes to the
line common and the two ends can be connected to the live either independently or both together.
Thus with an external switch that has four positions, it is possible to obtain 3 different light levels or to
switch off.
Existing Ballast Solutions
There are in existence CFL ballast designs that perform the same task. A common approach is a
system whereby the line voltage is full wave rectified when one live input is connected and a voltage
doubler circuit comes into operation when the other live input is connected or both are connected
together thereby having two DC bus voltages in the ballast during dim level settings. This type of
design also operates at two different frequencies, a low frequency (typically 40-45kHz) when both
live inputs are connected providing a high lamp current and a higher frequency (for example 70-
75kHz) when either of the two lives is connected alone which will produce a lower lamp current. In this
way the following combinations are achieved:
2
120V AC Line
Neutral
1. Low DC bus (150V) / high frequency
2. High DC bus (300V) / high frequency
3. High DC bus (300V) / low frequency
Live
3 Way Dimming Switch
…… maximum output
….. minimum output
…... medium output
3 Way Dimming Light Bulb
40W Filament
60W Filament
IRPLCFL4
www.irf.com