DC/DC boost converter with 0.7V input

Texas Instruments introduced a 2-MHz DC/DC boost converter that operates at 5 µA of quiescent current, while maintaining a high efficiency at light load conditions. The integrated circuit supports an input voltage of 0.7 V to 5.5 V and an output voltage range of 1.8 V to 5.5 V, extending battery life in low-power microcontroller-based designs, such as single AA or coin-cell alkaline applications. The TPS61220 boost converter, which comes in a SC-70 package, provides full battery capacity utilization of a portable system, because of its ability to start up with a 0.7-V input voltage into a connected load. Based on a hysteretic, off-time control method, the device uses synchronous rectification to maintain more than 85 percent power efficiency at the lowest possible operating current. This allows microcontroller-based applications, such as those that use TI’s CC430 microcontroller and low-power RF on a chip, to extend battery life by maintaining efficient standby operation.

 The TPS61220 provides output current up to 50 mA at a 5-V output, and discharge the system’s lithium-ion battery down to 2.5 V. The device’s output voltage can be programmed by an external resistor divider, or is fixed internally on the chip. In addition, the converter can be disabled to minimize battery drain. The TPS61220, which comes in a 6-pin, SC-70 package, can achieve a total DC/DC converter solution size of 6.4 x 9 mm with a height of 1 mm. The size allow designers to implement the device in any portable, microcontroller-based application powered by A, AA or AAA batteries.

 Pricing and Availability

 The TPS61220 boost converters are sampling today, and are scheduled to be available in volume by the end of 2008. Suggested resale pricing in quantities of 1,000 units is $0.65. TPS61xxx evaluation modules, application notes and TI’s DC/DC Quick Reference Guide are available.