IRPLCFL4 International Rectifier, IRPLCFL4 Datasheet - Page 10

• 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

10
The lamp filament (Cathode) resistance over the range of dimming levels should be between 3 and
5.5 times the resistance when cold. A simple method for determining the hot resistance is to first
connect one cathode to a DC power supply via an ammeter and slowly increase the voltage from
zero, noting the current at 1V intervals. This should be done until the cathode can be seen to be
glowing red. When this occurs the voltage should not be increased further in order to prevent pos-
sible cathode damage. The resistance can then be calculated for each voltage and hence the accept-
able voltage range can be found to comply with the 3 to 5.5 times cold resistance, which can be
easily measured with a DMM.
Then when the ballast is being run a true RMS digital voltmeter can be connected across one cathode
and the voltage can be observed at maximum and minimum brightness. The cathode voltage in-
creases as the ballast is dimmed. The values of C17 and C18 will control how much it increases by,
reducing the capacitance will reduce the amount by which the voltage rises. The values should be
chosen to prevent the voltage exceeding the upper limit at minimum output.
It is important to bear in mind that using additional windings on the inductor to provide cathode
heating means that power is now being transferred through the core and consequently the core
losses will increase and hence the core operating temperature. The core will reach its highest oper-
ating temperature when the ballast is running at minimum brightness.
The following component values have been selected for a 25W spiral compact lamp. The
circuit will need to be optimized for the particular lamp used to obtain best performance.
Bill of Materials
Item #
1
2
3
4
5
6
7
8
9
10
11
Qty
1
1
2
1
5
1
2
1
2
2
1
Manufacturer
National Semiconductor
International Rectifier
International Rectifier
On Semi
Microsemi
International Rectifier
Renco
B.I. Technologies
Panasonic
Panasonic
Panasonic
LM358AM
IR2156
IRF730
MURS160T
DL4148
DF10S
RL-5480-3-2700
HM00-01741
ECQ-E2104KB
EEU-EB2V220
ECE-AIVKG220
Part Number
Description
Dual Op Amp
Ballast Controller
MOSFET
600V 1A Fast
Diode SMD
Small Signal Diode
SMD
Bridge SMD
Filter Inductor
Inductor 2.2mH
EF20
100nF 200V
22uF 200V 105C
Electrolytic
22uF 35V 105C
Electrolytic
Reference
IC1
IC2
Q1,2
D8
D5,6,7,9,10
D1-4
L1,L2
L3
C1,2
C3,4
C7
IRPLCFL4
www.irf.com