Off-Line Linear Regulator Offers Adjustable Output Voltages

Designed for off-line power-supply applications, the LR8 three-terminal 450-V linear regulator has adjustable output voltages. This high-voltage, low-output current regulator suits telecom power supplies that encounter wide input-voltage variations...
March 5, 2001

Designed for off-line power-supply applications, the LR8 three-terminal 450-V linear regulator has adjustable output voltages. This high-voltage, low-output current regulator suits telecom power supplies that encounter wide input-voltage variations and high-voltage line transients.

The LR8's input voltage ranges from 12 to 450 V. Using two external resistors, its output voltage can be adjusted from 1.20 to 440 V when the input voltage is at least 10 V greater than the output. While the load regulation is ±3% for an output load of 0.5 to 10 mA, its maximum line regulation is 0.01%/V for any input line voltage between 15 to 400 V and a 5.0-V output. Maximum guaranteed output current is 10 mA.

Also, the LR8 features current limiting and thermal shutdown. The output current limit is 15 mA. Its minimum junction temperature limit is 125°C. It comes in 3-pin SOT-89 (LR8N8) and TO-92 (LR8N3) packages. In 1000-unit quantities, the LR8N8 costs $0.54, and the LR8N3 costs $0.52.

Supertex Inc., 1235 Bordeaux Dr., Sunnyvale, CA 94089; (408) 744-0100; www.supertex.com.

See associated figure.

About the Author

Sign up for Electronic Design Newsletters
Get the latest news and updates.

Voice Your Opinion!

To join the conversation, and become an exclusive member of Electronic Design, create an account today!