Monolithic Switching Regulators from Linear Technology

Linear Technology Corporation has announced the LT3513, a five output monolithic switching regulator packaged in a 5mm x 7mm QFN package. It offers a 2.2A (ISW) buck regulator, a 1.5A (ISW) boost regulator, a 250mA (ISW) boost regulator, a 250mA (ISW) inverter and an LDO controller, all in a single package. Each channel has an independent soft-start/run pin. The LT3513’s input voltage range of 4.5V to 30V makes it ideal for a wide array of TFT-LCD applications, including automotive, industrial and unregulated wall transformer-based systems. Its 2MHz switching frequency keeps switching noise out of critical frequency bands, such as AM radio, and ensures tiny externals. Combined with a 5mm x 7mm QFN package, the LT3513 offers a very compact TFT-LCD power solution.



The LT3513’s buck regulator can deliver up to 1.2A of output current for logic rails. A lower voltage secondary logic supply may be generated via the LDO controller and an external NPN MOSFET. A high power step-up converter (ISW=1.5A), a lower power step-up converter (ISW=250mA) and an inverting converter (ISW=250mA) provide the three independent output voltages: AVDD, VON and VOFF required by LCD panels. An integrated high side PNP provides a delayed turn on of the VON signal while Panel Protect circuitry disables VON if any of the four outputs are more than 10% below their programmed voltage, protecting the TFT-LCD panel. Other features include integrated schottky diodes, PGOOD pin for AVDD output disconnect and inductor current sense for the buck regulator.



The LT3513EUHF is available from stock in a 38-lead 5mm x 7mm QFN package. Pricing starts at $4.25 each in 1,000-piece quantities. An industrial grade version, the LT3513IUHF, is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $5.00 each in 1,000-piece quantities. All versions are available from stock.