Boost converter for harsh-environment battery applications
The Texas Instruments TPS61222MDCKTEP is a step-up (boost) DC-DC converter that delivers a fixed 5V output from an input as low as 0.7V and up to 5.5V. It integrates a 200mA switch and synchronous rectifier in a 6-pin SC-70-6 package.
What the 0.7V minimum input means for your battery selection
A 0.7V minimum input lets this part start up and regulate from a single alkaline cell (nominal 1.5V, end-of-life ~0.9V) or a Li-ion cell deep into discharge. The 5.5V input maximum covers USB power, 2-cell alkaline stacks, and regulated 3.3V or 5V rails without risk. The 200mA switch current limit sets a practical output power ceiling of roughly 1W at 5V — enough for a sensor node, RF transmitter, or small microcontroller rail.
Up to 2MHz switching — inductor sizing and noise
Switching at up to 2MHz lets the designer use small, low-profile inductors (typically 2.2µH to 4.7µH) and ceramic output capacitors, shrinking the total solution footprint. The synchronous rectifier improves efficiency at light loads compared to a diode-based boost, which matters for battery life in always-on applications. The high switching frequency pushes the fundamental switching noise above the AM radio band, simplifying input filter design in sensitive RF systems.