KA3842A − SMPS Controller

Obsolete as of 14-Sep-2013

The KA3842AC/KA3842AE are fixed PWM controller for Off Line and DC to DC converter applications. The internal circuits include UVLO, low start up current circuit, temperature compensated reference, high gain error amplifier, current sensing comparator, and high current totem pole output for driving a POWER MOSFET. Also KA3842AC/KA3842AE provides low start up current below 0.3mA and short shutdown delay time typ. 100ns. The KA3842AC/KA3842AE has UVLO threshold of 16V(on) and 10V(off). The KA3842AC/KA3842AE can operate within 100% duty cycle.

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Product Status/Packaging

Product Product & Eco Status Replacement Part Number Packaging & Packing Info **Package Marking Convention Qualification Support Compliance Certificates
2 KA3842ACS Obsolete as of 14-Sep-2013
ROHS Compliant
0.13 x 0.25 x 0.381mm

Line 1:$Y (Fairchild logo)
&Z (Plant Code)
&2 (2-Digit Date Code) &K
Line 2:KA3842A
FIT :  2.4  
RƟJA :  95  °C/W


  • Low Start Current 0.2mA (Typ)
  • Operating Range up to 500kHz
  • Cycle by Cycle Current Limiting
  • Under Voltage Lock Out With Hysteresis
  • Short Shutdown Delay Time: Typ.100ns
  • High Current Totem-Pole Output
  • Output Swing Limiting: 22V

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