Linear Technology has announced the LTC3543, a high efficiency, 2.25 MHz, synchronous buck regulator that can deliver up to 600mA of continuous output current from a 2mm x 3mm DFN package. The LTC3543 can run in either a constant 2.25MHz frequency, spread spectrum or synchronized phase lock loop (PLL) mode, offering multiple choices for very low noise operation. Its current mode architecture operates from an input voltage range of 2.5V to 5.5V, making it ideal for single cell Li-Ion, or multi-cell alkaline/NiCad/NiMH applications.
It can generate output voltages as low as 0.6V, enabling it to power the latest generation of low voltage DSPs and microcontrollers. Its 2.25MHz switching frequency enables the utilization of tiny, low cost ceramic capacitors and inductors less than 1mm in height, providing a very compact solution footprint for handheld applications.
The LTC3543 uses internal switches with an RDS(ON) of only 0.35Ohm (N-Channel) and 0.45Ohm (P-Channel) to deliver efficiencies as high as 95%. It also utilizes low dropout 100% duty cycle operation to allow output voltages equal to VIN, further extending battery run-time. For maximum light load efficiency, the LTC3543 utilizes an automatic Low Ripple (< 20mVPK-PK) Burst Mode® operation with only 45uA no load quiescent current. If the application is noise sensitive, the Burst Mode operation can be replaced with a lower noise pulse-skipping, spread spectrum or PLL (to an external clock between 1MHz and 3MHz) mode. In all modes, the device maintains shutdown currents of less than 1uA, maximizing battery run-time. Other features include ±2% output voltage accuracy, internal soft-start and over-temperature protection.
The LTC3543EDCB in available in a 2mm x 3mm DFN-6 package and is available from stock. Pricing starts at $1.95 each for both parts in 1,000-piece quantities.