IRPLHALO1E International Rectifier, IRPLHALO1E Datasheet - Page 3

• 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
The IR2161 provides low and high side output drives for the half-bridge MOSFETs or IGBTs. The
output from the half bridge is connected to a high frequency stepdown transformer, which supplies
approximately 12Vrms at the output to drive the lamps. The IR2161 also incorporates all of the
protection features needed in the system without the need for very many external components.
At switch on the frequency sweeps from a high frequency around 125kHz down to the normal
operating frequency 30 to 40kHz over a period of approximately 1 second. Because of the leakage
inductance in the transformer this causes the output voltage at the lamp to start at a reduced value
and gradually increase to the 12V nominal level. This reduces the inrush current at switch on. When
the lamp is cold the filament resistance is lower which tends to cause high inrush currents that can
cause false tripping of the shutdown circuit.
The IC includes a short circuit protection that operates if a high current is detected for approximately
50mS causing the outputs to switch off. Similarly if an >50% overload is detected for more than
approximately 500mS then the outputs will switch off. It should be noted that the shutdown time
under an overload condition will be reduced depending on the magnitude of the overload.
This dual mode shutdown circuit will protect the circuit from all output fault conditions and will
function when the convertor is dimmed, unlike the self-oscillating solution and it will also protect the
system from a short circuit at the end of the output leads.
An electronic transformer is normally required to provide a reasonably consistent output voltage
over a range of loads and so the IC senses the load through the current sense resistor and in-
creases the frequency as the load is reduced thus providing compensation for the output trans-
former load regulation. There is also some modulation of the frequency through the line voltage
half-cycle to spread the harmonics and reduce the size and cost of the EMC filtering components
required.
The IR2161 includes all necessary protection features and also allows the convertor to be dimmed
externally with a standard phase cut dimmer for leading or trailing edge. This IC provides the advan-
tage of longer lamp life due to soft start and output voltage shift (load regulation) compensation. It
causes the convertor to run with optimized harmonic behavior (i.e. almost unity power factor) also
at higher loads (solution with bipolar devices can have harmonics problems for high loads due to
the fact that the oscillator start-stop every half cycle, causing cross over distortion).
The IC also includes adaptive dead time to realize soft-switching and allow cool running MOSFETs
(and improves the EMI behavior due to frequency modulation during the line voltage half cycle).
Some points to consider when comparing a Halogen convertor circuit design with an electronic ballast
for fluorescent lamps:
www.irf.com
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