The LTC3639 is a 150V input-capable synchronous buck converter that delivers up to 100mA of continuous output current. It operates from an input voltage range of 4.5V to 150V, eliminating the need for an external transient suspension device.The LTC3639 utilises internal synchronous rectification and a programmable peak current-mode design to optimize efficiency over a broad range of output currents. It delivers efficiencies as high as 92% and requires only 12µA of quiescent current, maximizing battery run time and eliminating thermal issues.A user-programmable output current limit can set output current from 10mA to 100mA thereby minimizing the need to oversize external components and protecting high impedance sources. The LTC3639 can be programmed with fixed output voltages of 1.8V, 3.3V or 5V or a resistor divider can be used to program outputs from 0.8V to VIN.The LTC3639's thermally enhanced MSOP package offers the additional pin spacing required for high voltage inputs. The combination of its MSOP package with only three tiny externals provides a highly compact solution footprint for a broad range of applications.The internal high side and synchronous power switches of the device, drawing only 12µA at no load while maintaining output voltage regulation, make it ideal for always-on battery-powered applications.Pricing for the LTC3639EMSE starts at $3.65 each. An industrial version the LTC3639IMSE is guaranteed to operate from -40°C to 125°C operating junction temperature, priced at $4.02 each.An automotive version the LTC3639HMSE is guaranteed to operate over -40°C to 150°C is priced at $4.27 each while a high reliability military plastic version, the LTC3639MPMSE, is tested and guaranteed to operate from -55°C to 150°C, is priced at $10.84 each. All pricing is for 1,000 piece quantities.
