PJ3845

T PJ3844B / PJ3845B High Performance Current Mode Controller he PJ3844B , PJ3845 series are high performance fixed frequency current mode controllers. This is specifically cycle-by-cycle current limiting , programmable output deadtime, and a latch for single pulse metering. Allowing output deadtimes to be programmed from 50% to 70%. This device is available in 8-pin dual-in-line plastic packages as well as the 8-pin plastic surface mount (SOP-8). The SOP-8 package has separate power and ground pins for the totem pole output stage. The PJ3844B is tailored for lower voltage applications having UVLO thresholds of 16V (on) 10V (off). ThePJ3845B is tailored for lower voltage applications having UVLO thresholds of 8.5V(on) and 7.6V(off). designed for Off-Line and DC-to-DC converter applications offering the designer a cost effective solution with minimal external components.This 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, FEATURES Trimmed Oscillator Discharge Current for Precise Duty Cycle Control Current Mode Operation to 500KHz Automatic Feed Forward Compensation Latching PWM for Cycle-By-Cycle Current Limiting Internally Trimmed Reference with Undervoltage Lockout High Current Totem Pole Output Input Undervoltage Lockout with Hystersis Low Start-Up and Operating Current Pin：1. Compensation Pin：2. Voltage Feedback Pin：3. Current Sense Pin：4. RT/CT DIP-8 SOP-8 5. Gnd 6. Output 7. Vcc 8. Vref ORDERING INFORMATION Device PJ3844/3845BCD PJ3844/3845BCS Operating Temperature (Ambient) -20℃ TO +850C Package DIP-8 SOP-8 SIMPLIFIED BLOCK DIAGRAM Pin numbers adjacent to terminals are for the 8-pin dual-in-line package. Pin numbers in parenthesis are for the SOP-8 package The document contains information on a new product.Specifications and information herein are subject to change without notice. 1-14 2004/11. Rev B PJ3844B / PJ3845B High Performance Current Mode Controller MAXIMUM RATING Parameter Supply Voltage (low impedance source) Supply Voltage (Ii