07 March 2003
High efficiency dc/dc converters
High efficiency dc/dc converters suiting a range of applications are being unveiled by a number of companies. Ultimate Renaissance boasts a 20W single output device with an output efficiency of 83% and an output ripple of 50mV. The AET04, produced by Asdec, come in voltages of 18 to 36V dc or 36 to 72V dc. The device comes with short circuit protection with a continuous power cycle, offers a transient response time of 250us and voltage trims from 90 to 110%. It operates at between –40 and 105oC and meets UL, CSA and TUV requirements.
Rohm’s latest dc/dc converters offer efficiencies up to 93% and can operate without a heatsink. The BP523xxxA series comes in current options of 2, 3 and 4A, and provides for step down from a 5V input to either 2.5 or 3.3V. Typical output voltage ripple is 33mV.
For inductor free pump dc/dc converters, Microchip is shipping the MCP1252 and MCP1253 – providing a fixed 3.3 or 5.5V output or an adjustable output voltage of 1.5 to 5.5V from a 2.7 to 5.5V input source.
The devices have a drain current of 60uA, a shutdown current of 0.1uA and a power good output that can detect an out of regulation situation with an output voltage accuracy of ±2.5% maximum.
The MCP1252 has an operating frequency of 650kHz, avoiding critical system frequencies, whilst the MCP1253 operates at 1MHz – minimising the external component size.
Finally, 35W sub quarter brick dc/dc converters from BTCPower are available from Hunter Electronic Components. Input voltages range from 18 to 36V or 36 to 75V. The device, which offers an efficiency of up to 90%, has output voltages of 1.5, 1.8, 2.5, 3.3, 5 or 12V.
Go to the Ultimate Renaissance web site
Go to the Rohm Electronics web site
Go to the Microchip Technology web site
Go to the Hunter Electronic Components web site