Using an "always-on" ultra-low-power system controller can significantly reduce power consumption on portable devices like handsets and tablets. These controllers can act as sensor hubs and monitor user stimuli (for example, reading inertial sensors or touch sensors) and vital system parameters like battery health and temperature, while power-hungry application processors and touch screen controllers are turned off. The microcontroller can then "wake up" the system based on a user input or on a fault condition that requires CPU intervention.
The MSP430F525x series is the latest addition to the 1.8-V split-rail I/O portfolio (previously only available on MSP430F522x) and is specifically designed for "always-on" system controller applications. 1.8-V I/O allows for seamless interface to application processors and other devices without the need for external level translation, while the primary supply to the MCU can be on a higher voltage rail.
Compared to the MSP430F522x, the MSP430F525x provides up to four times more RAM (32KB) and double the serial interfaces (four USCI_A and four USCI_B). The MSP430F525x also features four 16-bit timers, a high-performance 10-bit ADC, a hardware multiplier, DMA, a comparator, and an RTC module with alarm capabilities. The MSP430F525x consumes 290 µA/MHz (typical) in active mode running from flash memory, and it consumes 1.6 µA (typical) in standby mode (LPM3). The MSP430F525x can switch to active mode in 3.5 µs (typical), which makes it a great fit for "always-on" low-power applications.
Key benefits of the MSP430F525x are as follows:
- Up to 32KB of RAM allows complex sensor hub algorithms and high levels of aggregation such as keyboard control and power management.
- Four USCI_A and four USCI_B modules allow for eight concurrent dedicated hardware serial interfaces (for example, four I2C and four SPI) for fast and robust communication to sensors or peripheral devices.
- Up to 35 I/Os that can be used in the 1.8-V voltage rail.
For complete module descriptions, see the MSP430F5xx and MSP430F6xx Family Users Guide. For design guidelines, see Designing With MSP430F522x and MSP430F521x Devices.