Both versions have input ranges up to 36Vdc and outputs from 3V3 to 15V. Operating temperatures range from -40 to +85°C and efficiencies are up to 95% with no requirements for additional heatsinks, even when operating at +85°C.

They also exhibit low ripple and low noise operation (typically 50mV pp) and a MTBF of >2,000,000 hours. Short circuit protection is standard in all models and the K78xx-500R3-LB additionally has negative output capability. All regulators are RoHS-compliant.

The switching regulators are supplied in an industry-standard SIP3 package and are pin-compatible with LM78xx linear regulators while the K78xxJT-500R3-LB series buck converters are supplied in a 12.00 x 12.00 x 4.50mm surface mount package and can be supplied either in tubes or tape and reel.


Typical applications are cost-sensitive and with limited available space such as instrumentation, robotics, street lighting and the IoT, which all require reliable non isolated dc-dc conversion.

Both linear regulator families are available with the industry’s shortest lead-times, says Relec, at four to six weeks in volume, and benchmark pricing.