IR21571 International Rectifier, IR21571 Datasheet - Page 15

• Manufacturer Part Number: IR21571
• Description: IC BALLAST CONTROL 16-DIP
• Manufacturer: International Rectifier
• Type: Ballast Controllerr

Specifications of IR21571

• Frequency: 45.5 ~ 50.5 kHz
• Current - Supply: 5.5mA
• Current - Output: 500mA
• Voltage - Supply: 11.4 V ~ 15.6 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *IR21571

IR21571 (S) & (PbF)
Figure 16: Hard switching condition
Figure 18: Auto restart for lamp replacement
Recovery from such a fault condition is accomplished
by cycling either the SD lead or the V
lead. When
CC
a lamp is removed, the SD lead goes high, the fault
latch is reset, and the chip is held off in an unlatched
state. Lamp replacement causes the SD lead to go
low again, reinitiating the startup sequence. The fault
latch can also be reset by the undervoltage lockout
signal, if V
falls below the lower undervoltage
CC
threshold.
Bootstrap Supply Considerations
Power is normally supplied to the high-side circuitry
by means of a simple charge pump from V
, as
CC
shown in Figure 19.
Figure 17: Operation below resonance
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