Data Sheet

ADPL42005

analog.com

Rev. 0

21 of 26

junction temperature drops below 135°C, the output is turned on again, and output current is restored to its

operating value.

Consider the case where a hard short from VOUT to ground occurs. At first, the ADPL42005 current limits, so that only

775mA is conducted into the short. If self heating of the junction is great enough to cause its temperature to rise

above 150°C, thermal shutdown activates, turning off the output and reducing the output current to zero. As the

junction temperature cools and drops below 135°C, the output turns on and conducts 775mA into the short, again

causing the junction temperature to rise above 150°C. This thermal oscillation between 135°C and 150°C causes a

current oscillation between 775mA and 0mA, which continues as long as the short remains at the output.

Current and thermal limit protections are intended to protect the device against accidental overload conditions. For

reliable operation, device power dissipation must be externally limited so the junction temperature does not exceed

125°C.