The CS284XA, CS384XA provides all the necessary features to implement off�line fixed frequency current�mode control with a minimum number of external components. The CS384XA family incorporates a new precision temperature�controlled oscillator with an internally trimmed discharge current to minimize variations in frequency. A precision duty�cycle clamp eliminates the need for an external oscillator when a 50% duty�cycle is used. Duty�cycles greater than 50% are also possible. On board logic ensures that VREF is stabilized before the output stage is enabled. Ion implant resistors provide tighter control of undervoltage lockout. Other features include low startup current, pulse�by�pulse current limiting, and a high�current totem pole output for driving capacitive loads, such as the gate of power MOSFET. The output is LOW in the off state, consistent with N�channel devices. The CS384XA series of current�mode control ICs are available 8 and14 lead packages for surface mount (SO) applications as well as 8 lead PDIP packages. Features Optimized for Off�line Control Internally Trimmed Temperature Compensated Oscillator Maximum Duty�Cycle Clamp VREF Stabilized Before Output Stage is Enabled Low Startup Current Pulse�By�Pulse Current Limiting Improved Undervoltage Lockout Double Pulse Suppression 1.0% Trimmed Bandgap Reference High Current Totem Pole Output

DIP�8 N SUFFIX CASE SO�8 D SUFFIX CASE SO�14 D SUFFIX CASE 751A WL, L YY, Y WW, 3 = Assembly Location = Wafer Lot = Year = Work Week CSx84yA AWLYWW 8 x84yA ALYWX x84yA AWL YYWW

See detailed ordering and shipping information in the package dimensions section on page 8 of this data sheet.

& SO�8 COMP VFB Sense OSC 8 1 VREF VCC VOUT GND COMP NC VFB NC Sense NC OSC SO�14 14 VREF NC VCC Pwr VOUT Pwr GND

Rating Supply Voltage (ICC < 30 mA) Supply Voltage (Low Impedance Source) Output Current Output Energy (Capacitive Load) Analog Inputs (VFB, Sense) Error Amp Output Sink Current Package Thermal Resistance, PDIP�8 Junction�to�Case, RJC Junction�to�Ambient, RJA Package Thermal Resistance, SO�8 Junction�to�Case, RJC Junction�to�Ambient, RJA Package Thermal Resistance, SO�14 Junction�to�Case, RJC Junction�to�Ambient, RJA Lead Temperature Soldering: 1. 10 second maximum. 2. 60 second maximum above 183�C. *The maximum package power dissipation must be observed. Wave Solder (through hole styles only) (Note 1) Reflow (SMD styles only) (Note 2) Value Self Limiting to peak 230 peak Unit V mA �CW �C

3. These parameters, although guaranteed, are not 100% tested in production. *Adjust VCC above the start threshold before setting 15 V.