Datasheet LT1083, LT1084, LT1085 (Analog Devices) - 10

LT1083/LT1084/LT1085
block DiagraM
VIN + – THERMAL LIMIT VOUT 1083/4/5 ADJ BD VADJ
applicaTions inForMaTion
The LT1083 family of 3-terminal adjustable regulators is on the output will ensure stability. Normally, capacitors easy to use and has all the protection features that are much smaller than this can be used with the LT1083. Many expected in high performance voltage regulators. They are different types of capacitors with widely varying charac- short-circuit protected, and have safe area protection as teristics are available. These capacitors differ in capacitor well as thermal shutdown to turn off the regulator should tolerance (sometimes ranging up to ±100%), equivalent the junction temperature exceed about 165°C. series resistance, and capacitance temperature coefficient. These regulators are pin compatible with older 3-terminal The 150µF or 22µF values given will ensure stability. adjustable devices, offer lower dropout voltage and more When the adjustment terminal is bypassed to improve the precise reference tolerance. Further, the reference stability ripple rejection, the requirement for an output capacitor with temperature is improved over older types of regula- increases. The value of 22µF tantalum or 150µF aluminum tors. The only circuit difference between using the LT1083 covers all cases of bypassing the adjustment terminal. family and older regulators is that this new family requires Without bypassing the adjustment terminal, smaller an output capacitor for stability. capacitors can be used with equally good results and the table below shows approximately what size capacitors are
Stability
needed to ensure stability. The circuit design used in the LT1083 family requires the
Recommended Capacitor Values
use of an output capacitor as part of the device frequency
INPUT OUTPUT ADJUSTMENT
compensation. For all operating conditions, the addition of 10µF 10µF Tantalum, 50µF Aluminum None a 150µF aluminium electrolytic or a 22µF solid tantalum 10µF 22µF Tantalum, 150µF Aluminum 20µF 108345fh 10 For more information www.linear.com/LT1083 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Block Diagram Applications Information Typical Application Package Description Revision History Typical Applications Related Parts