Industrial, Connectivity Kinetis KM3x MCU Single-Phase Metering Reference Design Based on high-performance, 24-bit sigma-delta ADC Overview modules of the meter such NVM memories, tamper events include two tamper switches With the growing consumption of energy for data logging and firmware storage, a protecting the main and terminal covers. An low-power, 3-axis Xtrinsic tilt sensor for additional optional tamper event is generated an electronic tamper detection and an RF by a low-power, 3-axis Xtrinsic tilt sensor. communication module for AMR and remote With the tilt sensor populated, metering solutions. The Kinetis M series single-phase monitoring. electronics are powered when coordinates electricity meter reference design addresses The backup battery is used to power the these accuracy and cost needs by providing meter electronics in case of power loss. a high-performance analog front end (24- This battery will activate the meter in case bit AFE) combined with an embedded the user button is pressed or a tamper programmable gain amplifier (PGA) to increase event occurs. The permanent sources of worldwide, particularly in the residential market, utility providers need increasingly accurate and cost-effective energy metering of the installed meter unexpectedly change. The tilt sensor in the meter not only prevents physical tampering but can also power meter electronics to disconnect a house from the mains in case of an earthquake. the accuracy of energy measurement, along with a cost-effective shunt sensing circuit implementation and bill of materials (BOM). Kinetis Series One-Phase Meter Reference Design Kinetis MM Series One-Phase Power Power Meter Reference Design The single-phase meter reference design is 32 kHz used for measurement and registration of active and reactive energy in single-phase two-wire networks for direct connection. It is 1, EN50470-3, class B and C, as well as to IEC 62053-21 and IEC 62052-11 international UMI Connector 110/220 V L_OUT pre-certified according to European EN50470- SR L_INP LCD 22 x 4 I Sense PGA+SD0 standards for electronic meters of active energy classes 2 and 1. The integrated switched mode power supply (buck converter) enables efficient operation of the meter electronics and provides enough power for optional Voltage Divider Power Supply SMPS 85–264 VAC/3.3 V 3.3 V Battery V Sense SD2 RTC SPI SPI Flash (128 KB) SCI Debug RS232 (Isolated) KM34 50 MHz CM0+ 128 KB Flash SCI IR Readout (IEC61107) SPI External NVM (4 KB) 100 LQFP IC Temp. Sensor SCI 2 RF Sub GHz/ZigBee® I2C N_INP Control Button Freescale Technology GPIO Tamper Detect Upper Cover Lower Cover Optional GPIO MMA8491Q Tilt Sensor GPIO Open Collector Pulse kWh Pulse kVARh Pulse The 32-bit MKM34Z128 Kinetis MCU at the heart of the reference design is based on the ARM® Cortex™-M0+ core. This efficient processor core with support for 32-bit math enables fast execution of filter-based metering • Single built-in mechanical button as control interface Documentation • An upper and lower tamper meter cover monitoring with time stamp stored in meter logbook in external NVM (optional) • Filter-based algorithm for metering application algorithms. • Isolated (4 kV) RS232 port for monitoring, parameterization and firmware upgrade Reference Design Features • LED pulse outputs (kWh, kVarh) • MKM34Z128 Kinetis MCU built on the ARM Cortex-M0+ core • IEC1107 infrared hardware interface • 5 to 80 A current range (nominal current is 5 A, peak current is 80 A) • 85 to 264 V, 50/60 Hz voltage range • Accuracy class: B or C (active energy EN50470-3) and 3 or 2 percent (reactive energy EN62053-23) • Line frequency measurement (for precision zero-cross detection) • Cost-effective shunt-resistor sensing circuit implementation • Low-power modes including the use of built-in RTC (lithium battery backup) • 4 x 22 segment LCD, including charge pump (values shown on LCD: V, A, W, Var, VA, kWh, kVarh, cos F, Hz, time, date) • Design reference manual • FFT-based algorithm for metering applications (AN4255) • Low-level on-chip peripheral drivers • Hardware schematic diagram • Reference design quick start guide • RF connector supporting sub-GHz or 2.4 GHz 802.15.4 communications for AMR and remote control (KW01 or KW20 wireless MCU module optional) Related Products • Low-power, 3-axis Xtrinsic tilt sensor for electronic tamper detection (optional) • Efficient ARM Cortex™-M4 CPU with up to 512 KB flash • EMC proven design (EN61000-4-2, EN610004-4) • Low RF power consumption TX (0 dBm) 15 mA and RX 15 mA • Cost-effective bill of materials (BOM) • Dual PAN and antenna diversity support with +10 dBm output power and –102 dBm sensitivity Software Provided • Multiple advanced metering algorithms Filter-based FFT method • MQX™ real-time operating system KW20 Wireless 2.4 GHz MCUs (Optional) • Support IEEE 802.15.4-compliant radio with ZigBee®, 6LowPAN, WirelessHART and ISA 100.11a stacks • Comprehensive peripheral library drivers KW01 Wireless Sub-GHz MCUs (Optional) KM34Z128 MCU Features • Efficient ARM Cortex-M0+ CPU with up to 128 KB flash • Up to 50 MHz ARM Cortex M0+ core with up to 128 KB flash and 16 KB RAM • Ultra-low-power mode with 1.7 μA/4.3 μs wake-up time • Highest resolution AFE with 4 x 24-bit SD ADC with 94 dB SNR • High RF budget link up to +137 dBm • Built-in VREF and PGA with low drift over temperature • Four UART, two SPI and two I C with IRDA and 7816 support 2 • Two analog comparators • Single low-cost 32 kHz crystal for MCU and RTC • Support of WM bus, 802.15.4g/e MMA8491Q Xtrinsic 3-Axis MEMS Tilt Sensor (Optional) • Miniature 3 mm x 3 mm QFN • Low current consumption: 400 nA at 1 Hz sample rate • 14-bit accelerometer data • Auto compensated RTC with high-speed calibration with high accuracy and 0.88 ppm resolution (1 Hz output pulse) • Security with active tamper, memory protection unit • Up to 4 x 40 and 8 x 36 segment LCD Kinetis KM3x Single Phase Metering Reference Design For more information, visit freescale.com/metering Freescale, the Freescale logo, Kinetis and Xtrinsic are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. All other product or service names are the property of their respective owners. ARM is a registered trademark of ARM Limited. ARM Cortex-M4 and ARM Cortex-M0+ are trademarks of ARM Limited. © 2012 Freescale Semiconductor, Inc. Document Number: KNTSKINMFS REV 0