New Semtech EcoSpeed™ DC-DC Converters Provide Ultra-Fast Transient Response and High Efficiency Across the Full Load Range

The SC173 and SC174 converters use Semtech’s EcoSpeed architecture to achieve the best of conventional current mode, voltage mode and constant on-time control topologies, with minimal tradeoffs. This architecture enables ultra-fast transient response and very high efficiency across light to full power loads, while eliminating the need for external compensation components, providing a simple, space-saving and cost-effective power management solution. [sc173_174]



The EcoSpeed architecture uses an advanced control loop to dynamically adjust the on-time based on input voltage and output voltage. This approach enables a pseudo-fixed frequency operation with ±15% accuracy and very predictable EMI -- comparable to conventional voltage mode and current mode topologies, and better than constant on-time and hysteretic architectures where frequencies are unpredictable.



The SC173 and SC174 EcoSpeed converters are programmable from 200kHz to 1MHz allowing designers to optimize their power supply to maximize either the conversion efficiency or the solution size. They also incorporate Semtech’s proprietary SmartDrive™ technology, which is a two-step, high-side FET turn-on technology designed to reduce EMI in noise-sensitive applications.



Very low power during standby mode is increasingly important to comply with emerging “green” initiatives. However, most electronic products also require fast “wake-up” capability, which demands fast recovery from low-power standby to full-power steady state mode. The SC173 and SC174 EcoSpeed converters solve this challenge with an ultrasonic power-save (UPSAVE) mode. UPSAVE lowers the switching frequency to cater to low-power standby requirements, thereby by reducing the switching losses associated with the power FET gate charge. This results in up to 95% peak standby efficiency. Then, when the load changes from standby to steady state, the EcoSpeed technology cycle-by-cycle response quickly exits UPSAVE mode providing very fast power-up response time. Additionally, UPSAVE ensures that the device switching frequency stays above the 25kHz threshold, thereby eliminating audible resonance.



The EcoSpeed architecture allows the SC173 and SC174 to work with ceramic input and output capacitors, providing design flexibility and reliability. This, combined with no external compensation components optimizes BOM costs and reduces customers’ time-to-design. The SC173 and SC174 offer output currents of 3A and 4A respectively and are packaged in a 10-pad, 3.0 x 3.0 x 1.0 mm, lead-free, halogen-free MLPD package for further space savings.



“Achieving power efficiency during standby mode, while providing ‘instant-on’ and high operating efficiency presents a tremendous challenge in meeting today’s green power initiatives,” said Alan Burchfield, Senior Product Marketing Manager for Semtech’s Power Management Group. “Our EcoSpeed DC-DC converters help designers easily and cost-effectively solve these issues. The EcoSpeed platform represents the next step in our commitment to delivering unmatched power management solutions for emerging green electronic product requirements.”

Key Features of the SC174 and SC173 EcoSpeed DC-DC Converter



* Ultra-fast transient response

* Very high efficiency across light to full power loads

* No external compensation components required

* Ultrasonic PSAVE: up to 95% peak efficiency during light loads

* Pseudo-fixed switching frequency with ±15% accuracy (programmable 200kHz to 1MHz)

* SmartDrive™ technology reduces EMI

* VIN: 3V to 5.5V; IOUT: 3A (SC173) & 4A (SC174)

* Fully protected with output OVP, UVP and short circuit protection

* 10-pad MLPD package - 3.0 x 3.0 x 1.0 mm





The SC173 and SC174 join Semtech’s existing family of higher voltage, higher current EcoSpeed DC-DC converters, providing the same adaptive on-time architecture benefits for lower voltage, lower current point-of-load applications. Additional devices in the family include ultrasonic power-save devices: SC414 (6A), SC417 (10A), SC418 (30A controller with low dropout regulator), SC419 (30A controller); as well as standard power-save devices: SC424 (6A) and SC427 (10A).