4-140V buck converter delivers up to 400mA continuous output

It utilises an internal 1.8Ω power MOSFET for robust, high efficiency operation. A user-programmable output current limit can set output current from 100 to 400mA as required by the particular application. The LTC7138 can be programmed with fixed output voltages of 1.8, 3.3 or 5V, or a resistor divider can be used to program outputs from 0.8V to V_IN.

The LTC7138’s thermally enhanced MSOP offers the additional pin spacing required for high voltage inputs. The combination of its MSOP and only four tiny externals provides a compact solution footprint for a wide array of applications. The LTC7138 is available in a thermally enhanced high voltage-capable 16-lead MSE package with four missing pins.

The LTC7138 draws only 12µA at no load while maintaining output voltage regulation, suiting it for always-on battery-powered applications. Due to the inherent stability of the converter, no external compensation is required thereby simplifying design and minimising the solution footprint. Additionally, features include a precise 0.8V ±1% feedback voltage reference, 100% duty cycle dropout operation and, internal or external soft-start, and a feedback comparator output which enables multiple LTC7138s to be connected in parallel for higher current applications.

Pricing for the LTC7138EMSE starts at $3.80 per unit. An industrial temperature version, the LTC7138IMSE, is guaranteed to operate from a -40 to +125°C operating junction temperature and is priced at $4.18. Furthermore, an automotive temperature version, the LTC7138HMSE, is specified to operate from a -40 to +150°C operating junction temperature and is priced at $4.43 each. A high reliability version, the LTC7138MPMSE, is tested and guaranteed to operate from a -55 to +150°C operating junction temperature and is priced at $11.29 each. All pricing is for 1,000-piece quantities and all versions are available from stock.