Step down regulator enables easy current sharing

The new switching regulator architecture uses a 50µA current reference, combined with a single resistor to set the output voltage. According to Linear, the unique design enables easy current sharing between multiple regulators, setting the output voltage for all of the regulators with a single external resistor. The LTC3600 has a wide input voltage capability from 4 to 15V and is suitable for dual-cell Li-Ion applications. It has fixed 5V and 12V intermediate bus systems and, according to Linear, has synchronous rectification delivers efficiencies as high as 96%. The novel design is said to allow dynamic adjustment of output voltage from 0 to V_IN 0.5V, while the device's ability to provide zero output enables it to power down individual rails in the system as needed. Its on chip trimmed reference achieves accuracy of ±1%. Output regulation and transient response are independent of output voltage. Output voltage tracking or soft start can be programmed via the ISET pin for applications that require power sequencing. According to Linear, the LTC3600's wide V_IN & V_OUT capability, tight line and load regulation, high efficiency, low external parts count and parallel capability make it ideal for modern multirail systems. The device combines a 3 x 3mm DFN / thermally enhanced MSOP-12 package with a 200kHz to 4MHz switching capability, enabling use of tiny, low cost capacitors and inductors. Additional features include a power good voltage monitor, external synchronisation capability and thermal protection. There are two industrial grade versions, the LTC3600EDD - available in a 3 x 3mm DFN-12, and the LTC3600EMSE - in a 12lead, thermally enhanced MSOP package. Both devices are guaranteed to operate over the -40 to 125°C operating junction temperature range.