UC3843AN2

Enabling Energy Efficient Solutions Product Overview Created on: 10/26/2011 UC3842B: High Performance Current Mode PWM Controller For complete documentation, see the data sheet Product Description The UC3842B, UC3843B series are high performance fixed frequency current mode controllers. They are specifically designed for Off-Line and dc-to-dc converter applications offering the designer a cost-effective solution with minimal external components. These integrated circuits feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering. These devices are available in an 8-pin dual-in-line and surface mount (SO-8) plastic package as well as the 14-pin plastic surface mount (SO-14). The SO-14 package has separate power and ground pins for the totem pole output stage. The UCX842B has UVLO thresholds of 16 V (on) and 10 V (off), ideally suited for off-line converters. The UCX843B is tailored for lower voltage applications having UVLO thresholds of 8.5 V (on) and 7.6 V (off). Features • • • • • • • • • • Trimmed Oscillator for Precise Frequency Control Oscillator Frequency Guaranteed at 250 kHz Current Mode Operation to 500 kHz Automatic Feed Forward Compensation Latching PWM for Cycle-By-Cycle Current Limiting Internally Trimmed Reference with Undervoltage Lockout High Current Totem Pole Output Undervoltage Lockout with Hysteresis Low Startup and Operating Current Pb-Free Packages are Available Part Electrical Specifications Product Compliance Status Topolog y Control Mode fsw Typ (kHz) Standby Mode UVLO (V) Short Circuit Protecti on Latch Soft Start VCC Max (V) Drive Cap. (mA) Packag e Type UC3842BD1G Pb-free Active Flyback Current Mode 52 No Yes Yes No No 30 200 / 200 SOIC-8 Active Flyback Current Mode 52 No Yes Yes No No 30 200 / 200 SOIC-8 Active Flyback Current Mode 52 No Yes Yes No No 30 200 / 200 SOIC14 Active Flyback Current Mode 52 No Yes Yes No Yes 30 200 / 200 SOIC14 Active Flyback Current Mode 52 No Yes Yes No No 30 200 / 200 PDIP-8 Active Flyback Current Mode 52 No Yes Yes No Yes 30 200 / 200 SOIC-8 Active Flyback Current Mode 52 No Yes Yes No No 30 200 / 200 SOIC-8 Active Flyback Current Mode 52 No Yes Yes No Yes 30 200 / 200 SOIC14 Halide free UC3842BD1R2G Pb-free Halide free UC3842BDG Pb-free Halide free UC3842BDR2G Pb-free Halide free UC3842BNG Pb-free Halide free UC3842BVD1G Pb-free Halide free UC3842BVD1R2G Pb-free Halide free UC3842BVDR2G Pb-free Halide free Package Availability Type PDIP-8 SOIC-8 SOIC-14 Pb-free Standard ✓ ✓ ✓ For more information please contact your local sales support at www.onsemi.com