For applications in extreme ambient temperatures, Linear Technology has created "H-grade" and "MP-grade" versions of the LT3580, a current-mode, fixed frequency step-up DC/DC converter with internal 2A, 42V switch. The device operates from an input voltage range of 2.5V to 32V, making it suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs.
The H-grade version operates with a junction temperature range of -40°C to 150°C, whereas the MP-grade operates with a junction temperature range of -55°C to 125°C. This compares to the E- and I-grade versions' 125°C maximum junction temperature. All electrical specifications are identical for the E, I, H and MP. The H-grade parts are both tested and guaranteed to the junction temperature range of -40°C to 150°C and are suited for automotive and industrial applications, which are subject to high ambient temperatures. Similarly, the MP-grade parts are tested and guaranteed to the junction temperature range of -55°C to 125°C and thus can be deployed in military and avionics applications, which are subject to both low and high ambient temperatures, the company says.
The LT3580 can be configured as either a boost, SEPIC or an inverting converter. Its switching frequency can be programmed, via a single resistor or synchronized to an external clock, between 200kHz and 2.5MHz, enabling designers to minimize external component sizes and to avoid "noise critical" frequency bands. The combination of an MSOP-8E package and tiny externals ensures a highly compact footprint while minimizing solution cost.
Other features include adjustable switching frequency and a high gain SHDN pin which accepts slowly varying input signals. In addition, the devices are synchronizable to external clock.
The LT3580HMSE and the LT3580MPMSE are available from stock in thermally enhanced MSOP-8E packages. Pricing starts at $2.77 and $8.31 each, respectively, for 1,000-piece quantities.