IRPLCFL4 International Rectifier, IRPLCFL4 Datasheet - Page 7

• 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 closed loop regulation dimming ballast section is identical to that used in the reference design
IRFPCFL3. Since we are sensing the lamp arc current with a resistor it is necessary to use voltage
mode preheating so as to avoid detecting the sum of the current in the arc and that in the resonant
output capacitor C16. This has an additional advantage that during preheat and prior to ignition of the
lamp the arc current will always be zero and consequently the feedback circuit will not influence the
oscillator frequency at all until the lamp is running. This means that by setting the value of R17 the
preheat will occur in exactly the same way regardless of which of the live inputs are connected, thus
achieving optimum preheat and ignition under all conditions.
In an integrated CFL design it is not necessary to include R21, R9 and C19 which detect lamp
removal or open lower cathode, pin 9 of IC2 SD can be connected directly to COM. Although it is
recommended to retain the current sense and shut down at the half bridge provided by R19, R20 and
C11, in an integrated CFL these could also be left out and pin 10 CS could be connected directly to
COM.
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COMMON
L1
L2
R5
R4
R1
L1
C1
L2
C2
R2
C3
C4
D1
D3
R6
D2
D4
C7
R7
R8
5
6
R10
R12
2
3
IC1a
R11
8
4
R9
C8
7
IC1b
1
C20
D7
R3
R18
R15
Circuit Schematic
R16
R17
C9
VCC
VDC
RPH
CPH
NC
RT
CT
C10
1
2
3
4
5
6
7
IC2
D8
C6
14
13
12
11
10
9
8
COM
HO
VB
VS
LO
CS
SD
C5
C11
R19
Q1
Q2
R20
C13
D10
L3
C19
R21
C14
D9
R13
C15
R9
C12
C16
IRPLCFL4
D5
R14
C18
C17
L3a
L3b
D6
7