ICE 1QS01 Controller for Quasiresonant Switch Mode Power Supplies Supporting Low Power Standby and Power Factor Correction

Features

• 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 Voltages

• 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

Functional Description

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 overand 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.

Absolute Maximum Ratings

P-DIP-8-4 P-DSO-8-3

Block Diagram

Pin Configuration (top view)