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 1.5μA)

● Low Operating Current (about 2.2mA)

● Current Mode Operation

● Under Voltage Lockout (UVLO)

● Built-in Synchronized Slope Compensation

● Built-in fixed soft start with 1.2mS

● Built-in Frequency jitter 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-23-6L、 SOP8 and DIP-8 Pb-Free Packaging Compatible with SG6848 (6849) / SG5701 / SG5848 / LD7535 (7550) / OB2262 (2263) / OB2278（ 2279）

● Soft Clamped GATE output voltage 16.5V

● VDD over voltage protect 25.6V

● Cycle-by-cycle current limiting

● Sense Fault Protect ion

● OTP (Over Temperature Protection)

● 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

● 384X Replacement