AnalogicTech Offers New Chip Scale Packages For DC-DC Converters

Advanced Analogic Technologies Inc. (AnalogicTech) announced the availability of Chip Scale Packages (CSPs) for its AAT1149 and AAT1171 dc-dc converters. By eliminating bond wires, the new CSP option is said to offer a dramatic reduction in footprint. The company claims that the new packaging option also reduces stray inductance, capacitance and resistance and therefore noise, compared to traditional packaging with bond wires.

"CSP has quickly evolved from an interesting packaging innovation to a mainstream packaging technology," said Bill Weiss, Product Line Director at AnalogicTech. "By taking advantage of lower component profiles, reduced stray inductance, capacitance and resistance and enhanced electrical characteristics, these new packages will enable designers of cell phones, Bluetooth™ headsets and other space-constrained portable systems to reduce footprint, improve ac performance, and drive down manufacturing costs."

The AAT1149 was originally introduced in a 2 x 2.1mm 8-pin SC70JW package. At 1.235 x 0.91mm, the new CSP option reduces the required PCB footprint by 73%. Similarly, the AAT1171, originally introduced in a 3 x 3mm 12-pin TDFN package, is now available in a CSP which, at 1.5 x 2.2mm, reduces the required PCB footprint by 64%, when compared to the original package.

Targeted at meeting tight portable design space requirements, the AAT1149 step-down converter delivers up to 400mA of load current from a 2.7 to 5.5V input while operating with low profile, 1mm high 0603 inductors. Output voltage is programmable via external feedback resistors from 1.0V to VIN. The device attains up to a high 98% efficiency. No load quiescent current is only 45µA.

The AAT1171 is a dynamic voltage-scaling dc-dc converter optimized to support Power Amplifiers (PAs) in WCDMA and CDMA handsets. Operating across a wide 2.7 to 5.5V input voltage range, the device delivers up to 600mA of continuous load current. The converter optimizes PA efficiency at both low and high transmit levels by supplying a variable output voltage of 0.6 to 3.6V. No load quiescent current is only 45µA. The company claims that using an AAT1171 step-down converter can result in a 60% power savings when compared to connecting the PA directly to the system battery and thereby dramatically increase the talk-time of the mobile handset.

Both the AAT1149 and AAT1171 are qualified across the -40 to +85°C temperature range. In a CSP the AAT1149 sells for $0.87 in 1K quantities and the AAT1171 sells for $1.31 in 1K quantities.