Dual 2-phase Synchronous Controller Drives a Range of MOSFETs

Linear Technology’s LTC3736-2 is a 2-phase dual synchronous stepdown switching regulator controller with output tracking that drives a wide range of external power MOSFETs. Its 2.75-V to 9.8-V input range enables it to operate from single-cell Li-Ion, multicell NiCd/NiMH and fixed 5-V inputs. It can deliver outputs as low as 0.6 V. The LTC3736-2's constant frequency current mode architecture with MOSFET V_DS (drain-to-source voltage) sensing eliminates the need for sense resistors while improving efficiency. By operating the two controllers out of phase, both power loss and noise due to the ESR of the input capacitor are minimized.

The LTC3736-2's switching frequency can be programmed up to 750 kHz, allowing the use of small surface-mount inductors and capacitors. For noise-sensitive applications, the LTC3736-2 switching frequency can be externally synchronized from 250 kHz to 850 kHz using a phase locked loop (PLL). Pulse skipping operation provides high efficiency at light loads while 100% duty cycle capability provides low dropout operation, extending operating time in battery-powered systems. Other features include an internal soft-start, Power Good Output voltage monitor and overvoltage protection.

The LTC3736EUF-2 is available from stock in a 4-mm × 4-mm QFN-24 package. Pricing starts at $3.90 each for 1000-piece quantities.