TechBites Says:

Silicon Labs’ selection of a sub-GHZ operating frequency for its new family of wireless controllers was a smart move since its increased range and penetration make it a great fit for lots of smart building/Smart Grid applications. Coupled to a 25 MHz 8051 core and a nice collection of analog I/O, the Si10xx wireless MCUs feature a transmitter that can put out up to +20 dBm output power without the need for external PA. The radio’s –121 dBm receive sensitivity greatly increases range and, according to SiLabs, give their parts a – 141 dB link budget. Its on-chip synthesizer/PLL mixer is fully programmable allowing the radio to support operation from 240 MHz to 900 MHz. Among other things, this makes it one of the first wireless controllers capable of operating on China’s new 500 MHz band.

The controller’s 8051 core is complimented by an 18-channel 12-bit A/D, a current-mode DAC, and 2 programmable comparators. SiLabs has also packed a 25 MHz precision oscillator, a precision voltage reference, and an integrated temp sensor onto the chip to help cut the BOM costs of most common sensor applications. The processor also features architectural enhancements aimed at improving performance and power efficiency. 75% of the core’s instructions now execute in two clock cycles or less, enabling much better code efficiency.

To maximize battery life, SiLabs used a collection of aggressive tricks to squeeze every last microwatt out of their design. For example, they’ve carefully segmented the system’s functional elements so that they only have to power up the ones that are actually in use at a particular moment. They’ve also used low-leakage high voltage transistors for anything running in sleep mode so that regulator can be disabled. This trims the processor’s active mode power to 160 µA/MHz and trims its sleep mode power to; 315 nA when its using its internal LFO RTC. Adding an external precision 32.768 kHz RTC raises sleep mode power to 615 nA.

 The power numbers that Silabs showed me indicate they beat TI’s CC430 and CC1110 family in sleep mode by a wide margin – mostly thanks to being able to run off their LDO.The processor’s deep sleep mode offers two options. In its brown-out protect mode that retains the RAM’s contents, the sleeping processor draws only 65 nA. If brownout protection is not necessary, this can be trimmed to a mere 25 nA.

 By using a combination of a boost-mode switcher and an LDO, the power supply can deliver the 1.8 V needed for the for MCU and up to 3.3 for radio operation off a single 1.3V cell. For low-load conditions (sleep mode or MCU only) the system disables the switching supply and runs solely on the LDO. At loads of 10mA or more, the chip activates the switcher which enjoys efficiencies of around 95% at these higher current levels. Including a boost mode converter allows manufacturers to power their designs off a single low-cost alkaline cell instead of a more costly lithium stack. In many cases, this can dramatically cut a design’s BOM cost without sacrificing operational life. In many applications, the battery’s chemistry may be the limiting factor (around 5-7 years for alkaline and a bit longer for lithium-based cells).

 The low power consumption also makes these processors a good candidate for deriving their power from energy scavenging systems. While SiLabs has no definite plans for releasing a reference design with an energy scavenging system, they did say that they have begin investigating their options. I’d expect to see an ambient-powered version that contains battery management and energy scavenging electronics on board if SiLabs ever commits to a particular technology. To help push them along, I’ve given them contacts at Excellatron, a company founded by my friend Lonnie Johnson, which has a very promising technology for LiIon batteries that can be printed directly on a PCB or other flat surface.

 The Si10xx family’s exceptional battery life and its frequency-agile radio give it some significant potential advantages over TI’s excellent TMS430 wireless controller family for many wireless applications, including security, smart home, and mart metering of energy, gas or water. While they don’t enjoy as extensive development ecosystem as the TI products do, the tools and eval kits that Silabs does offer seem to be very adequate and fully-featured enough to support nearly development task. Their Si1000DK and Si1010DK dev kits accept test cards with radios optimized for the 915, 868, 433 MHz bands. The platforms are equipped with Silicon Labs’ IDE-compliant Wireless Development Suite (WDS) and their EZMac -networking in a box protocol stack that supports generic peer-2-peer, star and simple mesh configurations.. SiLabs also has a stack for the wireless M-Bus MAC protocol (popular in Europe).

 Pricing for the Si10xx MCUs starts at $3.51 (USD) in 10K quantities. Sampling now, with full production in 2Q 2010. The Si1000DK development kit is available now for $99 (USD). The WIRELESSMBUSEK evaluation kit is priced at $99 (USD). For additional product information and to purchase samples and development tools, please visit www.silabs.com/pr/wirelessmcu.

Silicon Labs Says:

 -- Single-Chip Solution Ideal for Battery-Powered Systems with RF Connectivity --

  Answering the need for energy efficiency in home automation and metering, Silicon Laboratories Inc. has introduced the industry’s lowest power single-chip wireless microcontrollers (MCUs). Silicon Labs’ new ultra-low-power Si10xx wireless MCU family addresses the power and RF requirements of battery-operated home automation systems, smart meters, in-home utility monitors and security systems.

The demand for smart energy technology continues to grow each year as government initiatives mandate upgrades to the grid, as well as adding intelligence to meters that measure water, gas and heat. The market for smart home products, such as lighting and HVAC controls, in-home utility monitors and home security systems, is also on the rise, driven in part by the desire to conserve energy and by the expansion of home automation services and standards-based wireless technologies.

Today’s smart home/smart grid applications merge wired/wireless connectivity and embedded control with power-efficient design to maximize battery life. The ultra-low-power Si10xx wireless MCU family is ideally suited for these battery-operated systems with RF links, as well as for many other embedded wireless applications that require ultra-low power consumption.

The Si10xx wireless MCUs combine a 25 MHz 8051 core, EZRadioPRO sub-GHz RF transceiver, up to 64 kB of flash and up to 12-bit ADC – all in a compact 5 mm x 7 mm package. The Si10xx family is the industry’s most power-efficient single-chip wireless MCU solution, providing the lowest current in common modes of operation. The wireless MCUs offer the lowest active-mode current consumption (160 microamps per MHz). In sleep mode, they consume only 610 nanoamps with an active 32.768 kHz real-time clock (RTC) and down to 315 nanoamps with an active RTC and a low frequency oscillator (LFO). In deep-sleep mode, they can operate on as little as 25 nA with full RAM retention.

The Si10xx family’s ultra-low-power architecture and fast wake-up time (2 microseconds) greatly extends battery life in both lithium and alkaline battery applications. The Si10xx architecture also features a dc-dc boost converter designed to supply large loads with extremely high efficiency. The dc-dc converter supplies power needed for periods of RF transmission and reception with efficiencies of up to 90 percent. As a result, developers can design embedded wireless systems capable of 25 percent longer battery life over alternative solutions with no degradation in MCU or radio performance; in some system configurations, an Si10xx device can extend battery life by as much as 50 percent.

The Si10xx wireless MCUs offer market leading RF performance with the highest output power and sensitivity and lowest power wake-up transition. The Si10xx family’s integrated power amplifier (PA) and low-noise amplifier enable an RF link budget of greater than 140 dB without requiring active external elements. This results in extended range, higher bandwidth and lower overall power consumption.

“The Si10xx family is a battery’s best friend, offering best-in-class energy efficiency that makes it easier to design battery-powered products for the smart home and smart meter markets,” said Mark Thompson, vice president and general manager of Silicon Labs’ Embedded Mixed Signal products. “By incorporating the EZRadioPRO transceiver, the Si10xx wireless MCUs deliver exceptional RF performance with high output power and superior sensitivity.”

Unparalleled Development Support

To streamline the development of smart home and smart meter products based on Si10xx wireless MCUs, Silicon Labs offers a rich set of hardware and software tools for MCU and system design, RF design and optimization, and network software design. These tools include the following:

• Si1000-DK and Si1010-DK development kits
• SDBC-DK3 development platform for EZRadioPRO wireless products
• Wireless development suite (WDS), a comprehensive toolset that makes it easy to develop robust, low-cost wireless applications with little or no specific RF design experience
• EZMACPRO media access control module (“network in a box”)
• Fully compliant wireless M-Bus stack (EN: 13757-4), a metering networking standard common in Europe