C8051F96x Ultra Low Power MCU Ideal for Metering & Power Budget-conscious Applications
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The C8051F96x family is the lowest power, most advanced MCU solution for power sensitive embedded systems used in battery-powered and green energy applications. The C8051F96x family has been designed from the ground up to seamlessly interoperate with Silicon Labs’ EZRadioPRO® sub-GHz transceivers.
The C8051F96x implements the following three primary strategies to address each “slice” of the power budget:
- Reduce active mode time
- Reduce sleep mode power
- Improve efficiency of moving energy from the battery to the system
Reduce active mode time
The microcontroller consumes much more power in active mode than it does in sleep mode so anything that either accelerates the processing (i.e., decreases the time) of active mode or can perform that same function without having to be in active mode is useful.
- AES encryption/decryption hardware—dedicated encryption hardware that is approx. 500 times faster than performing a similar function in software.
- Cyclic Redundancy Check (CRC) hardware—moving this function to hardware allows CRC to be generated in a fraction of time compared to software CRC generation.
- Manchester and three-out-of-six encoder hardware— provides hardware blocks for both the Manchester and three-out-of-six schemes required by the M-Bus specification which ensures frequent line voltage transitions directly proportional to the clock rate and helps in clock recovery. Using dedicated peripherals is an extremely power efficient way to encode data.
- Direct Memory Access (DMA)—the DMA peripheral allows the MCU to perform a complete radio transaction without CPU intervention and ensures proper sequencing of these steps without burdening the CPU.
- Low power pulse counter—features a low power pulse counter that performs switch closure or pulse train functions autonomously in sleep mode without CPU intervention.
Reduce sleep mode power
The features above target power consumption by quickly and efficiently moving the system from active mode to sleep mode. The section below covers innovations to minimize power during sleep mode.
- Optimized power consumption of Real Time Clock (RTC)—the RTC block is 15% lower power than previous designs and 40% less than the best MCU competitive product – it is the lowest power RTC in the industry!
- Low Frequency Internal Oscillator (LFO) option for RTC—an LFO was added to further reduce sleep mode current that can use the LFO for most of the time and periodically switch to the crystal based upon environmental conditions.
- Three independent RTC alarms—provides a more flexible way for designers to schedule events and allows an application to remain in sleep mode for a greater portion of the time.
- Ultra-low-power integrated LCD—includes a 32 x 4 segment LCD controller results in lower LCD power consumption for both static as well as multiplexed applications.
Improve efficiency of moving energy from battery to system
The most compelling and unique feature of the C8051F96x is the integrated dc-dc buck converter. This block offers much higher efficiency of voltage conversion compared to a linear regulator and does not impact part performance.