February 5, 2014 – Linear Technology Korea (CEO Hong Sa-kwak) announced the release of a high-efficiency buck converter (product name: LTC3638) capable of 140V input.

This product provides a continuous output current of up to 250mA. The LTC3638 operates over an input voltage range of 4V to 140V and is ideally used in telecom, industrial, aviation, and automotive applications.

The LTC3638 utilizes internal synchronous rectification and a programmable hysteric mode design to optimize efficiency over a wide range of output currents. It offers high efficiency of 88% and requires a standby current of only 12µA, maximizing battery operating time.

The user-programmable output current limit can be set from 20mA to 250mA depending on application requirements. The LTC3638 can be programmed with a fixed output voltage of 1.8V, 3.3V, or 5V, and a resistor divider can be used to program the output in the range of 0.8V to VIN.

The LTC363's thermally enhanced skip-pin MSOP package provides the additional pin clearance required for high-voltage inputs. The combination of this product's MSOP package and just four small external components offers a very compact solution footprint for a wide range of applications.

The LTC3638 utilizes an internal high-side and synchronous power switch to maintain output voltage regulation while consuming only 12µA under no-load conditions. This makes it ideal for always-on battery-powered applications. Thanks to the converter's inherent stability, external compensation is not required. Therefore, the design is simplified and the solution footprint is minimized. Additional features include a 0.8V +1% precision feedback voltage reference, internal or external soft start, and feedback comparator output, which allow multiple LTC3638s to be connected in parallel for high-current applications.

The price of the LTC3638EMSE starts at $3.65 per unit. The industrial temperature version, the LTC3638IMSE, is guaranteed an operating junction temperature of -40°C to 125°C and is priced at $4.02 per unit. The automotive temperature version, the LTC3638HMSE, is guaranteed to operate at an operating junction temperature of -40°C to 150°C and is available for $4.27 per unit.

Finally, the high-reliability military-grade plastic version, LTC3638MPMSE, is tested and guaranteed to meet operating junction temperature specifications of -55°C to 150°C and is supplied for $10.84 per unit. All prices are based on a quantity of 1,000 units, and all versions are available immediately.

Photo Caption: 140V, 250mA Synchronous Buck Converter