Using an MSP430™ MCU and TPS60313 to Implement a Single-Battery-Cell Powered Thermostat

Powering an MSP430™ microcontroller (MCU) from a single 1.5-V battery cell is desirable in a number of applications. These applications require the use of a charge-pump-based dc/dc converter. This application report describes dc/dc converter basics and selection, and presents the implementation of a single-cell thermostat using an MSP430 MCU and a TPS60313 dc/dc converter. Analysis of the single-cell plus dc/dc converter solution includes the current consumption and the expected battery life.

Source code related to this solution is available for download from www.ti.com/lit/zip/slaa398.

Trademarks

MSP430 is a trademark of Texas Instruments.

All other trademarks are the property of their respective owners.

1 Introduction

With a properly selected charge pump, the designer can implement a single-cell powered application and still maintain low-power performance and battery life. The thermostat that is described in this application report is based on the MSP430F4794 MCU and the TPS60313 dc/dc charge pump converter, which is optimized for low-power single-cell applications. The MSP430F47x4 is a high-pin-count microcontroller with many peripherals. This application requires only one of the four SD16 modules (used to sample temperature) and the Basic Timer (used for periodic wakeup). It is left to the reader to decide how functionality can be added to take full advantage of the device’s feature set.

Figure 1. System Overview