Datasheet KA278RXXC (ON Semiconductor) - 3

Vin Q1 1 2 Vin Vo OVERVOLTAGE
PROTECTION THERMAL SHUTDOWN THERMAL SHUTDOWN -BANDGAP REFERENCE Q1 1 BANDGAP REFERENCE + 4 + Rin SOA PROTECTION SOA PROTECTION
HIGH / LOW
Vdis OVERVOLTAGE
PROTECTION + R1 2 Vo OUTPUT
ON / OFF
4 Vadj R2
1.4V SHORTCIRCUIT
PROTECTION SHORTCIRCUIT
PROTECTION Rref 3 3 GND GND Figure 1. KA278R33 / 05 / 12C Figure 2. KA278RA05C Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The
absolute maximum ratings are stress ratings only. Values are at TA = 25°C unless otherwise noted. Symbol Parameter VIN Input Voltage Vdis Disable Voltage IO Output Current Value
KA278RXXC Unit 35 V 35 V 2.0 A PD1 Power Dissipation 1 No Heat-Sink 1.5 W PD2 Power Dissipation 2 With Heat-Sink 15 W 150 °C Tj Junction Temperature Topr Operating Temperature Rθjc Thermal Resistance, Junction-to Case(1) Rθja Thermal Resistance, Junction-to-Air -20 to 80 °C 2.9 °C/W 48.51 °C/W Note:
1. Junction-to-case thermal resistance test environments:
-Pneumatic heat sink fixture;
-Clamping pressure 60 psi through 12 mm diameter cylinder;
-Thermal grease applied between PKG and heat sink fixture. © 2004 Fairchild Semiconductor Corporation
KA278RXXC-Series Rev. 1.1.0 www.fairchildsemi.com
2 KA278RXXC-Series — 2 A Output Low Dropout Voltage Regulators Block Diagram