Linear Technology offers a variety of devices that simplifyconverting power from a USB cable, but the ltC®3455represents the highest level of functional integration yet. The ltC3455 seamlessly manages power flowbetween an AC adapter, USB cable and Li-ion battery,while complying with USB power standards, all from a4mm × 4mm QFN package. In addtion, two high efficiencysynchronous buck converters generate low voltage railswhich most USB-powered peripherals require. TheltC3455 also provides power-on reset signals for themicroprocessor, a Hot SwapTM output for poweringmemory cards as well as an uncommitted gain blocksuitable for use as a low-battery comparator or an LDOcontroller. The PCB real estate required for the entire USBpower control circuit and two DC/DC converters is only225mm2.
The ltC®3414 offers a compact and efficient voltage regulatorsolution for point of load conversion in electronicsystems that require low output voltages (down to 0.8V)from a 2.5V to 5V power bus. Internal power MOSFETswitches, with only 67mW on-resistance, allow theltC3414 to deliver up to 4A of output current with efficiencyas high as 94%. The ltC3414 saves space by operatingwith switching frequencies as high as 4MHz, enabling theuse of tiny inductors and capacitors.
Easy-to-use and compact point-of-load power suppliesare necessary in systems with widely distributed, highcurrent, low voltage loads. The ltC®3415 provides acompact, simple and versatile solution. It includes a pairof integrated complementary power MOSFETs (32mΩtop and 25mΩ bottom) and requires no external senseresistor. A complete design requires an inductor andinput/output capacitors, and that’s it. The result is a fast,constant frequency, 7A current mode DC/DC switchingregulator.
Many complex systems—such as telecom equipment,memory modules, optical systems, networking equipment,servers and base stations—use FPGAs and otherdigital ICs that require multiple voltage rails that muststart up and shut down in a specific order, otherwise theICs can be damaged. The ltC®2924 is a simple andcompact solution to power supply sequencing in a 16-pinSSOP package (see Figures 1 and 2).
Traditionally, an Electronic Circuit Breaker (ECB) comprisesa MOSFET, a MOSFET controller and a current senseresistor. The ltC®4213 does away with the sense resistorby using the RDS(ON) of the external MOSFET. The resultis a simple, small solution that offers a signifi cant lowinsertion loss advantage at low operating load voltage.The ltC4213 features two circuit breaking responses tovarying overload conditions with three selectable tripthresholds and a high side drive for an external N-channelMOSFET switch.
