Milpitas, Calif. Linear Technology has introduced the LTC3672B-1 and LTC3672B-2 synchronous step-down DC/DC converters with dual LDOs. Both parts offer a 400 mA, 2.25 MHz synchronous buck regulator and two 150 mA LDOs packaged in a 2 x 2-mm DFN.
The LTC3672B-1 provides a fixed 1.8-V output on the switching regulator and fixed 1.2-V and 2.8-V outputs for the LDOs, whereas the LTC3672B-2 offers a fixed 1.2-V output on the switcher and fixed 1.8-V and 2.8-V LDOs. Both parts are suitable for digital media broadcasting (DMB) and digital video broadcasting (DVB) chipsets found in the latest generation of cell phones and PDAs. The input voltage range of 2.9 V to 5.5 V makes them a good fit for single cell Li-ion powered applications.
The 1.2-V, 1.8-V and 2.8-V outputs are used to power I/O, memory and core voltages of the latest DMB, DVB processors, as well many standardized DSPs and microcontrollers. The buck regulator's 2.25-MHz switching frequency and the LDO designs enable the use of tiny, low-cost external devices, providing a compact footprint for handheld applications.
The LTC3672B's synchronous buck delivers efficiencies as high as 93% and constant frequency, current mode operation minimizes noise while offering fast transient response. The LTC3672B-1's LDOs can be powered from the synchronous switcher's output to maximize efficiency and reduce output ripple. Other features include internal soft-start and internal compensation. Both devices are available in an 8-lead 2 x 2-mm DFN package.
Linear Technology Corp. , 1-408-432-1900, www.linear.com