Provides adjustable rail-to-rail output & cable drop compensation



Linear Technology announced the release of a high-efficiency 60V, 4A synchronous buck regulator (product name: LTC3649) that integrates a fixed frequency, current-mode architecture, programmable output current, and output voltage. All of these features are configured with a single resistor. The company explained that the LTC3649 operates over an input voltage range of 3.1V to 60V, provides an adjustable rail-to-rail output voltage range of 0 to (Vin-0.5V), and offers a continuous output current of up to 4A.

Linear explained that the product's wide input and output voltage range is ideal for a wide range of test, measurement, and industrial applications, and that the LTC3649's proprietary design includes an internally generated 50µA current source at the ISET pin and can provide a low output of nearly 0V using a single external programming resistor.

Furthermore, the LTC3649 provides ±0.8% output voltage precision and programmable output current with ±4% precision without a sense resistor. Its switching frequency is user-programmable in the range of 300kHz to 3MHz, enabling the use of small, low-cost capacitors and inductors. Coupled in a 28-pin 4mm x 5mm QFN or thermally enhanced TSSOP package, the LTC3649 offers a very small solution footprint.

The LTC3649 uses internal power switches with RDS(ON) of only 100 mOhms and 50 mOhms to provide high efficiency of up to 95%. Burst Mode® operation provides high efficiency at light loads and requires only 440µA of standby current. For noise-sensitive applications, the LTC3649 can operate in forced continuous mode, providing very low output ripple. Additional features include ±4% precise output current monitoring, Power Good voltage monitoring, programmable cable drop compensation, external synchronization, and thermal protection.

The LTC3649EUFD is available in a 4mm x 5mm QFN-28 package, while the LTC3649EFE is provided in a 28-pin TSSOP package with enhanced thermal performance. The industrial-grade LTC3649IUFD and LTC3649IFE guarantee operation over an operating junction temperature range of –40°C to 125°C. They are priced at $5.65 per unit in 1,000-piece quantities. All versions are ready to use. For all information, please refer to www.linear.com/product/LTC3649.