UC3842A, UC3843A, UC2842A, UC2843A High Performance Current Mode Controllers The UC3842A, UC3843A series of high performance fixed frequency current mode controllers are specifically designed for UC3842A, UC3843A, UC2842A, UC2843A V 7(12) CC V V CC ref 5.0V Undervoltage Reference Lockout 8(14) R V ref V C R Undervoltage Lockout 7(11) R C T T Output Oscillator 6(10) 4(7) Latching Power Voltage PWM Ground Feedback + 5(8) Input 2(3) Error Current Output Amplifier Sense Compensation 3(5) Input 1(1) GND 5(9) Pin numbers in parenthesis are for the D suffix SOIC14 package. Figure 1. Simplified Block Diagram MAXIMUM RATINGS Rating Symbol Value Unit Bias and Driver Voltages (Zero Series Impedance, see also Total Device spec) V , V 30 V CC C Total Power Supply and Zener Current (I + I ) 30 mA CC Z Output Current, Source or Sink (Note 1) I 1.0 A O Output Energy (Capacitive Load per Cycle) W 5.0 J Current Sense and Voltage Feedback Inputs V 0.3 to + 5.5 V in Error Amp Output Sink Current I 10 mA O Power Dissipation and Thermal Characteristics D Suffix, Plastic Package Maximum Power Dissipation T = 25C P 862 mW A D Thermal Resistance, JunctiontoAir R 145 C/W JA N Suffix, Plastic Package Maximum Power Dissipation T = 25C P 1.25 W A D Thermal Resistance, JunctiontoAir R 100 C/W JA Operating Junction Temperature T + 150 C J Operating Ambient Temperature T C A UC3842A, UC3843A 0 to + 70 UC2842A, UC2843A 25 to + 85 Storage Temperature Range T 65 to + 150 C stg Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage may occur and reliability may be affected. 1. Maximum Package power dissipation limits must be observed.