Description
The RS2051 is a highly integrated low cost current mode PWM controller, which is ideal for small power current mode of offline AC-DC fly-back converter applications. Making use of external resistors, the IC changes the operating frequency and automatically enters the PFM/CRM (Cycle Reset Mode) under light-load/zero-load conditions. This can minimize standby power consumption and achieve power-saving functions. With a very low start-up current, the RS2051 could use a large value start-up resistor (2Mohms). Built-in synchronized slope compensation enhances the stability of the system and avoids sub-harmonic oscillation. Dynamic peak current limiting circuit minimizes output power change caused by delay time of the system over a universal AC input range.

FEATUREs
● Low Cost, PWM, PFM&CRM (Cycle Reset Mode)
● Low Start-up Current (about 3μA)
● Low Operating Current (about 1.2mA)
● Current Mode Operation
● Under Voltage Lockout (UVLO)
● Built-in Synchronized Slope Compensation
● Built-in fixed soft start with 1.2ms
● Built-in Frequency Jiggling for better EMI Signature
● Programmable PWM Frequency
● Audio Noise Free Operation
● Leading edge Blanking on Sense input
● Constant output power limiting for universal AC input Range
● SOT-26、 SOP-8 and DIP-8 Pb-Free Packaging
● Soft Clamped GATE output voltage 18V
● VDD over voltage protect 34V
● Cycle-by-cycle current limiting
● Sense Fault Protect ion
● Output SCP (Short circuit Protection)
● Output OLP (Over Load Protection)
● Latch mode After OLP&SCP
● High-Voltage CMOS Process with ESD

APPLICATIONs
● Switching AC/DC Adaptor
● Battery Charger
● Open Frame Switching Power Supply
● Standby Power Supplies
● Set-Top Box Power Supplies