SBOS948F February 2019 – May 2021 BUF634A
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
Power dissipated in the BUF634A causes the junction temperature to rise. A thermal protection circuit in the BUF634A disables the output when the junction temperature reaches approximately 180°C. When the thermal protection is activated, the output stage is disabled and the output current is limited, allowing the device to cool. Quiescent current is approximately 12 mA during thermal shutdown. When the junction temperature cools to approximately 160°C, the output circuitry is again enabled. This process can cause the protection circuit to cycle on and off with a period ranging from a fraction of a second to several minutes or more, depending on package type, signal, load, and thermal environment.
The thermal protection circuit is designed to prevent damage during abnormal conditions. Any tendency to activate the thermal protection circuit during normal operation is a sign of an inadequate heat sink or excessive power dissipation for the package type.