Step-down regulator touts 55V transient protection

Linear Technology Corp. has released the H-grade version of the LT3641, a dual channel, current mode step-down switching regulator with power-on reset and a watchdog timer. According to the company, the device operates up to a junction temperature of 150°C and are ideal for industrial and automotive applications that are subject to high ambient temperatures.

Its 4-42V input voltage range, with 55V transient capability, makes the LT3641 ideal for load dump and cold crank conditions that require constant output regulation even with input transients as high as 55V, stated Linear Tech. The device uses a dual channel design with a high input voltage nonsynchronous channel that delivers 1.3A of output current, combined with a lower input voltage (2.5-5.5V_IN) synchronous channel that delivers up to 1.1A of continuous output current, added the company.

DC/DC converter offers 150°C max junction temp The LT3692A was also released recently by the company. The device is a monolithic, dual output step-down switching regulator that claims to offer up to 3.5A of continuous output current.

While the device allows separate inputs for each channel, most applications will use the output of the high voltage channel to power the lower voltage channel, offering dual outputs while optimizing efficiency and switching frequency. For example, using a nominal 12V input and a 2MHz switching frequency, the LT3641 can deliver a 3.3V output at 600mA with 85 percent efficiency via its high voltage channel and a 1.8V output at 800mA with 90 percent secondary conversion efficiency via its lower voltage channel.

The LT3641HFE is packaged in a 28-lead thermally enhanced TSSOP-28, priced starting at $4.43 each for 1,000 piece quantities.