IRS21571DSPBF International Rectifier, IRS21571DSPBF Datasheet - Page 17

• Manufacturer Part Number: IRS21571DSPBF
• Description: IC BALLAST CTRL 600V 16-SOIC
• Manufacturer: International Rectifier
• Type: Ballast Controllerr

Specifications of IRS21571DSPBF

• Frequency: 43.7 ~ 48.3 kHz
• Current - Supply: 10mA
• Current - Output: 180mA
• Voltage - Supply: 11.5 V ~ 15.6 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• Package: 16-lead SOIC Narrow
• Circuit: Fluorescent Ballast IC
• Offset Voltage (v): 600
• Output Source Current Min (ma): 180
• Output Sink Current Min (ma): 260
• Pbf: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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During the Startup Mode, the operating frequency is determined by the parallel combination of R
combined with the values of C
R
frequency. This frequency is high enough to ensure that the instantaneous voltage across the lamp during the
first few cycles of operation does not exceed the strike potential of the lamp. As the voltage at the R
decreases to the final value of 2V, the output frequency ramps down to the preheat frequency.
During the Preheat Mode, the operating frequency is determined by the parallel combination of R
combined with the value of C
ensure that adequate heating of the lamp filaments occurs. Typically, a 4.5:1 ratio of the hot filament-to-cold
filament resistance is desired for maximum lamp life, as shown in Figure 7 below
T
pin starts at an initial value above 2V, causing the initial start frequency to be higher than the preheat
Figure 6: Oscillator section block diagram with external component connection
R
C
T
C
IGN
T
C
T
PH
T
and R
R
and R
R
RUN
R
PH
DT
DT
CPH
RPH
RUN
DT
RT
CT
DT
. This frequency, along with the Preheat Time, is normally chosen to
2
3
4
5
6
7
, and the voltage at the R
7.6V
I
CT
I
= I
RT
5.1V
4.0V
RT
1.0uA
2.0V
17
4.0V
2.0V
T
pin, as shown in Figure 6. The voltage at the
VOLTAGE
R1
R2 Q
S
UNDER-
DETECT
Q
© 2008 International Rectifier
IRS21571D
PH
and R
PH
and R
T
,
T
pin
T
,