July 20, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the development of a high-efficiency 3MHz synchronous buck regulator (Product Name: LTC3626) capable of both input/output current limiting and monitoring. Featuring a unique constant frequency/control on-time, current-mode architecture, this product provides a continuous output current of up to 2.5A at a low output voltage of 0.6V in a 3mm x 4mm QFN package. Current-mode operation offers excellent line and load transient response along with a high step-down ratio.

Because the LTC3626 operates over an input voltage range of 3.6V to 20V, it is ideal for a variety of applications, including dual/multicell lithium-ion battery stacks and 5V to 18V intermediate bus systems. The average input and output current limits are pin-configurable, making it well-suited for applications such as USB power. The LTC3626's switching frequency is user-programmable and synchronized from 500kHz to 3MHz, enabling the use of inexpensive ultra-small capacitors and inductors.

The LTC3626 delivers high efficiency of 95% by utilizing internal switches with RDS(ON) of only 115mΩ and 70mΩ. Its unique architecture enables a low duty cycle of 5% while maintaining a switching frequency of up to 2.25MHz, making it ideal for high step-down ratio applications such as 12VIN to 1.2VOUT conversion. Burst Mode® operation is utilized to maximize light-load efficiency, consuming only 300µA under no-load conditions, which is critical for applications requiring maximum battery life. For applications requiring the lowest possible noise levels, the LTC3626 can be configured to operate in forced continuous mode, minimizing noise and potential RF interference. Additionally, the internal die temperature monitor provides temperature-proportional voltage that can be programmed to limit the maximum die temperature. Other features include a power good voltage monitor, output voltage tracking, and short-circuit protection.

The LTC3626EUDC is available in a 3mm x 4mm QFN-20 package. Pricing starts at $3.45 per unit for 1,000-unit orders. The industrial-grade version, the LTC3626IUDC, offers guaranteed performance over an operating temperature range of -40°C to 125°C and is priced at $3.97 per 1,000-unit order. Both versions are available immediately. For product details, please visit www.linear.com/product/LTC3626 .

Photo caption: LTC3626 providing up to 2.5A output current

Product Features: LTC3626
• 3.6V ~ 20V input voltage range
• Output voltage range: 0.6V to 97% of input voltage, optimized for 0.6V to 6V
• Provides up to 95% efficiency with a low RDS(ON) integrated switch
• Maximum output current of 2.5A
• Average I/O current monitoring
• Programmable average I/O current limit
• Die temperature monitor and programmable limit function
• Adjustable switching frequency: 500kHz ~ 3MHz
• External frequency synchronization
• Current mode operation for excellent line and load transient response
• 0.6V reference with 1% accuracy over the specified temperature range
• User-selectable Burst Mode® or forced continuous motion
• Short circuit protection function
• Output voltage tracking function
• Power Good status output
• Small 20-pin (3mm x 4mm) QFN package with enhanced heat dissipation performance