February 6, 2014 – Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of new products, including the high-reliability H-grade and military-grade MP versions of the high-efficiency, 4MHz synchronous buck regulator (product name: LTC3612). This product incorporates a constant frequency, current-mode architecture. The device is configurable to output voltages as low as 0.6V in 3mm x 4mm QFN or thermally enhanced TSSOP-20 packages and can provide a continuous output current of up to 3A. The LTC3612 operates from an input voltage of 2.25V to 5.5V and is ideal for single-cell lithium-ion applications as well as 3.3V or 5V intermediate bus systems. Switching frequencies are user-programmable from 300kHz to 4MHz, and small, low-cost capacitors and inductors can be utilized.

The LTC3612 achieves over 90% efficiency even in high step-down ratio applications, such as 5VIN to 1.8VOUT conversions, by utilizing built-in RDS(ON) switches with values of only 45mOhms and 70mOhms. Burst Mode® operation is used to maximize light-load efficiency and requires only 70µA under no-load conditions, making it ideal for applications requiring maximum battery operating time. An adjustable Burst Mode clamp allows designers to further optimize light-load efficiency. For applications requiring the lowest possible noise, the LTC3612 can be configured to operate in pulse skipping or forced continuous mode, reducing noise and potential RF interference. The LTC3612 provides inputs for tracking performance as well as DDR memory modes capable of source or sink up to +1.5A. Additional features include optional active voltage positioning, power good voltage monitoring, external synchronization performance, and thermal protection.

The high-reliability H-grade version guarantees compliance over an operating junction temperature range of -40°C to 150°C. The LTC3612HUDC is available in a 3mm x 4mm QFN-20, while the LTC3612HFE is provided in a 20-pin thermally enhanced TSSOP package. These products are priced at $3.95 and $4.15 per unit, respectively, in 1,000-unit quantities. The LTC3612MPUDC in the QFN package and the LTC3612MPFE in the TSSOP package are military-grade MP-grade versions that guarantee compliance over an operating junction temperature range of 55°C to 150°C and are priced at $9.85 and $10.40, respectively, in 1,000-unit quantities. All versions are available immediately.

Photo Caption: 3A, 4MHz synchronous step-down converter in 3mm x 4mm QFN & TSSOP packages