Controller for Switch Mode Power Supplies
Supporting Low Power Standby and
Power Factor Correction (PFC)
• Quasiresonant Operation
• Primary and Secondary Regulation
• Primary Current Simulation
• Standby Input Power < 1 W
• Low Power Consumption
• Very Low Start-up Current
• Soft-Start for noiseless Start-up
• Standby Burst Mode with and without Control Signal for lowered Output
• Digital Frequency Reduction in small Steps at Decreasing Load
• Over- and Undervoltage Lockout
• Switch Off at Mains Undervoltage
• Mains Voltage Dependent Fold Back Point Correction
• Ringing Suppression Time Controlled from Output Voltage
• Free usable Fault Comparator
The ICE1QS01 is optimized to control free running flyback converters with and without Power Factor Correction
(with PFC Charge Pump).
The switching frequency is reduced in small steps with decreasing load towards a minimum of 20 kHz in
standby mode. This function is performed by a digital circuit to avoid any jitter also with periodically pulsed
loads. To provide extremely low power consumption at light loads, this device can be switched into Standby
Burst Mode. This is also possible without standby control signal (for adapter application).
Additionally, the start up current is very low. To avoid switching stresses of the power devices, the power
transistor is always switched on at minimum voltage. The device has several protection functions: VCC over-
and undervoltage, mains undervoltage and current limiting. Regulation can be done by using the internal error
amplifier or an opto coupler feedback. The output driver is ideally suited for driving a power MOSFET.
The ICE1QS01 is suited for TV-sets, DVD- sets, SAT- receivers and other consumer applications in the power
range from 0 to app. 300 W.
DataSheet4 U .com
27 Apr 2004