IRPLHALO1E International Rectifier, IRPLHALO1E Datasheet - Page 6

• Manufacturer Part Number: IRPLHALO1E
• Description: KIT HALOGIN CONVERTER 100VA
• Manufacturer: International Rectifier

Specifications of IRPLHALO1E

• Main Purpose: Lighting, Ballast Control
• Utilized Ic / Part: IR2161
• Lead Free Status / RoHS Status: Lead free / RoHS non-compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Other names: *IRPLHALO1E

IRPLHALO1E
AC voltage to appear across the primary. The reduced output voltage will naturally result in a reduced
current in the lamp which eases the inrush current thus avoiding tripping of the shutdown circuit and
easing stress on the lamp filament as well as high current in the half bridge MOSFETs (M1 and M2).
The frequency sweeps down gradually from 125kHz to the minimum frequency over a period of
around 1s (for a CSD capacitor of 100nF). During this time the external capacitor at the CSD pin
charges from 0V to 5V controlling the oscillator frequency via the internal voltage controlled oscillator
(VCO). The value of CSD will determine the duration of the soft start sweep. However since it also
governs the shut down circuit delays the value should be kept at 100nF to achieve the correct
operation.
Fig. 2 Startup current without and with soft start function
Run Mode
When soft start is completed the system switches over to run mode. During this time the system
provides some regulation of the output voltage of the convertor from minimum to maximum load. In
this type of system it is desirable that the voltage supplied to the lamp does not exceed a particular
limit. If the lamp voltage becomes too high the temperature of the filament runs too high and the life
of the lamp is significantly reduced. The problem is that the output transformer is never perfectly
coupled so there will always be a degree of load regulation. The transformer has to be designed
such that the lamp voltage at maximum load is sufficiently high to ensure adequate light output.
At minimum load the voltage will consequently be higher and is likely to exceed the maximum
desired lamp voltage. The load current is sensed via the current sense resistor (RCS). The peak
current is detected and amplified within the IC then appears at the CSD pin during voltage compen-
sation mode. The voltage across the CSD capacitor will vary from 0V if there is no load to approxi-
mately 5V at maximum load.
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