Step-Down DC/DC Converter with Linear Controller in 3mm x 3mm DFN

Switching frequency is user programmable from 250kHz to 2.2MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The integrated LDO controller, combined with an NPN transistor, ensures very low noise output from the primary channel or as a second channel. The LT3500’s 3mm x 3mm DFN-10 package and high switching frequency, which keeps external capacitors and inductor small, provide a very compact, thermally efficient footprint.

The LT3500’s main switcher utilizes a high efficiency 2.3A, 450mVCESAT switch, with the necessary oscillator, control, logic circuitry and LDO controller integrated into a single die. Special design techniques enable high efficiency over a wide input voltage range while its current mode topology enables fast transient response and excellent loop stability. Other features include a power good flag and soft-start capability.

The LT3500EDD pricing starts at $3.25 each for 1,000-piece quantities. The LT3500IDD is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $3.90 each. The LT3500HDD is tested and guaranteed to operate from a -40°C to 150°C operating junction temperature and is priced at $4.15 each. All versions are available from stock.