Regulator for IC-core voltages achieves 97% efficiency

National Semiconductor has extended its PowerWise® converter family by adding the LM20145 5A synchronous buck regulator, which delivers an adjustable output voltage down to 0.8V from a 3.3V or 5V bus.

The LM20145 features integrated FET switches with 32mΩ on-resistance, which help the device achieve up to 97% efficiency. Two operating modes prevent excessive current at light loads: the device enters diode-emulation mode if the load current is less than half the peak-to-peak inductor ripple current, while pulse skipping reduces power consumption when the load current is less than 100mA.

The switching frequency is adjustable from 250kHz to 750kHz. The high operating frequencies minimise external component requirements, while accurate current-limit control allows a small inductor to be used. In addition, the 16-pin exposed-pad package minimises footprint and eliminates the need for a discrete heatsink.

The LM20145 is also easy to design in, and is stable with virtually any type of output capacitor. Only two external compensation components are typically required.

 

FEATURES Start-up sequencing Fault detection Adjustable soft-start Enable pin Under-Voltage Lockout (UVLO)

APPLICATIONS Processor boards for: Network infrastructure Telecom equipment High-performance computing

 

 

Development board LM20145EVAL is available to members of the Future Board Club. For more information, go to National's LM20145EVAL Product Page or alternatively if you would like to order a board go to http://www.my-boardclub.com/manf-offers.htm This offer is free and subject to qualification.

 

National LM20145 Synchronous Buck Regulator