CT-EM250 ZigBee-Ready RF Transceiver Modules ZigBee- Ready SoC RF Transceiver Modules Table of Content General Description2 Applications..2 Features2 Absolute Maximum Ratings...3 Recommended Operating Conditions..3 Electrical Specifications..3 Introduction...5 Typical Application Block....5 Pin Assignment.6 Block Diagram..8 Circuit Description8 SIF Module Programming and Debug Interface.9 Power Management9 RF Frequency, Output Power Levels and Data Rates10 Antenna Design Considerations..11 PCB Layout Recommendations..13 FCC Approvals...13 FCC statement .14 Operating description14 Mechanical Dimensions15 Ordering Information.15 Document Revision History..15 Computime Ltd. All rights reserved Confidential Page 1 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules ZigBee- Ready SoC RF Transceiver Modules General Description The CT-EM250 SoC RF Transceiver Modules is a compact surface mounted module specially designed for Embers ZigBee protocol stack for wireless networks, EmberZNet, based on IEEE 802.15.4 standard in the 2.4GHz world-wide ISM band. It provides 16 channels and compliant PHY and MAC layers. The complete module is only 20.32 x 25.52 x 3 mmintegrated antenna versionand 20.32 x 19.53 x 3 mm
(External Antenna version). They both integrate a 2.4GHz, IEEE 802.15.4-compliant transceiver with a 16-bit XAP2b microprocessor. They consist of integrated Flash and RAM memory and peripherals. A number of peripherals such as GPIO, UART, SPI, I2C, ADC, and general purpose timers are integrated to support user-defined applications. Applications Home automation &
building control Home appliances &
alarms Monitoring of remote systems Security systems
& lighting controls Sensor data capture in embedded networks IEEE 802.15.4 compliant PHY and MAC layer Features
Complete ZigBee-ready module with or without integrated antenna
12MHz XAP2b 16-bit microcontroller core
128kB Flash and 5kB RAM, emulation EEPROM
17 GPIO , 4 channel 12 bit ADC
UART, SPI, I2C and debug interfaces
External 32.768 kHz real time clock or internal RC oscillator for timer
High performance direct sequence spread spectrum (DSSS) RF transceiver
16 channels in the 2.4 GHz ISM band
on-chip regulator for 2.1-3.6V operation, two sleep low power modes Computime Ltd. All rights reserved Confidential Page 2 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Absolute Maximum Ratings Parameter Regulator voltage (VDD_PADS) Voltage on any GPIO[16:0], SIF_CLK, SIF_MISO, SIF_MOSI, nSIF_LOAD, OSC32A, OSC32B, nRESET, Storage temperature Under no circumstances should the absolute maximum ratings given above be violated. Stress exceeding one or more of the limiting values may cause permanent damage to the device. Test Conditions Min.
- 0.3
- 0.3 Max. 3.6 VDD_PADS+
0.3
+ 140
- 40 Unit V V C Recommended Operating Conditions Parameter Regulator input voltage (VDD_PADS) Core input voltage (VDD_24MHZ, VDD_VCO, VDD_RF, VDD_IF, VDD_PADSA, VDD_FLASH, VDD_PRE, VDD_SYNTH, VDD_CORE) Temperature range Test Conditions Min. 2.1 1.7 Typ. Max. 1.8 3.6 1.9 Unit V V
- 40
+ 85 C Electrical Specifications T=25, VCC = 3.0V, fo=2450Mhz, if nothing else stated. Parameter Operating frequency Typ. Max 2480 Min. 2405 Unit Condition / Note M Programmable in 5 MHz steps for IEEE 802.15.4 compliance Number of channels Channel spacing Input/output impedance Data rate DSSS chip rate Frequency stability Transmit power
-32 Harmonics 2nd harmonic 3rd harmonic 16 5 50 250 2
+/-40 5 TBD TBD MHz Ohm kbit/s Mc/s ppm dBm dBm dBm For IEEE 802.15.4 compliance For IEEE 802.15.4 compliance Programmable from firmware Computime Ltd. All rights reserved Confidential Page 3 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Min. Typ. Max Unit Condition / Note TBD TBD TBD TBD TBD TBD 3.6
-98 35/35 40/40
-6 36 36 1.0 1.5 128 5 8 12 10 32.768 dBm dBm dB dB dB dBm V mA mA A A KB kB kB MHz KHZ kHz Complies with EN 300 328, EN 300 440, FCC CRF47 Part 15 and ARIB STD-T66 PER = 1% Boost Mode IEEE 802.15.4 signal at - 82dBm IEEE 802.15.4 signal at - 82dBm IEEE 802.15.4 signal at - 82dBm Complies with EN 300 328, EN 300 440, FCC CRF47 Part 15 and ARIB STD-T66 Max RX sensitivity (boost mode) At max. TX power
(+ 5dBm boost) including internal RC oscillator including 32.768k oscillator Parameter Spurious emission, TX 30 1000 MHz 1-12.75 GHz 1.8-1.9 GHz 5.15-5.3 GHz Sensitivity Adjacent channel rejection
+/-5 MHz Adjacent channel rejection
+/-10 MHz Co-channel rejection Spurious emission, RX 30 -1000 MHz 1-12.75 GHz Supply voltage Current consumption, RX Current consumption, TX 2.1 Quiescent current, Mode1 Quiescent current, Mode2 Flash memory EEPROM OSCILATOR frequency low RAM memory Simulated memory MCU clock frequency RC FREQUENCY MCU crystal Computime Ltd. All rights reserved Confidential Page 4 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Introduction The CT-EM250 series of modules are specially designed for ZigBee application. They provide a fast jump start design for system integrators or electronic designers wishing to use ZigBee wireless technologies. The module contains qualified RF hardware and enough processor power to run the EmberZNet stack or other ZigBee network stack
(depending on version), making it a powerful platform for building wireless networking products. ZigBee Coordinators (ZC), ZigBee Routers (ZR), and ZigBee End Devices
(ZED) are all supported and are programmed onto the module together with a custom application. Minimal RF design experience is need to use CT-EM250 modules. Typical application block GPIO PIN MCU or/and Peripheral Equipment SIF PIN VDD_PADS=2.13.6V Debug and programming interface SIF PIN CT-EM2500 RF Module Hum. sensor Temp. sensor 4 General A/D pin Figure 1 Example of application block Pin Assignment Computime Ltd. All rights reserved Confidential Page 5 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Serial interface, master in/slave out Serial interface, master out/slave in Serial interface, load strobe (open-collector with internal pull-up) Direction Description O I I/O Ground Ground supply I/O I/O I/O I/O Ground Ground supply Ground Ground supply I/O Ground Ground supply I I/O Digital I/O Enable GPIO16 with GPIO_CFG[3]
Digital I/O Enable GPIO15 with GPIO_CFG[2]
Digital I/O Enable GPIO14 with GPIO_CFG[1]
Digital I/O Enable GPIO13 with GPIO_CFG[0]
receiver input/transmitter output Active low chip reset (internal pull-up) 24MHz crystal oscillator or left open when using external clock input on OSCA 24MHz crystal oscillator or external clock input Pads supply (2.1-3.6V) Digital I/O Enable GPIO11 with GPIO_CFG[7:4]
Digital I/O Enable GPIO12 with GPIO_CFG[7:4]
Digital I/O Enable GPIO0 with GPIO_CFG[7:4]
Digital I/O Enable GPIO1 with GPIO_CFG[7:4]
Digital I/O I/O Power I/O I/O I/O I/O I/O Computime Ltd. All rights reserved Confidential Page 6 of 15 Pin Description Pin# Signal 1 2 3 4 5 SIF_MISO SIF_MOSI SIF_LOADB GND GPIO16 GPIO15 GPIO14 GPIO13 GND GND ANT GND nRESET OSCB OSCA VBRD GPIO11 6 7 8 9 10 11 12 13 14 15 16 17 18 GPIO12 19 20 21 GPIO0 GPIO1 GPIO2 CT-EM250 ZigBee-Ready RF Transceiver Modules I/O I/O I/O I/O I/O I/O O I I Enable GPIO2 with GPIO_CFG[7:4]
Digital I/O Enable GPIO3 with GPIO_CFG[7:4]
Digital I/O Enable GPIO4 with GPIO_CFG[12] and GPIO_CFG[8]
Digital I/O Enable GPIO5 with GPIO_CFG[12] and GPIO_CFG[9]
Digital I/O Enable GPIO6 with GPIO_CFG[10]
Digital I/O Enable GPIO7 with GPIO_CFG[13] and GPIO_CFG[11]
Digital I/O Enable GPIO8 with GPIO_CFG[14]
UART transmit data of Serial Controller SC1 Enable SC1-4A or SC1-2 with GPIO_CFG[7:4], select UART with SC1_MODE UART receive data of Serial Controller SC1 Enable SC1-4A or SC1-2 with GPIO_CFG[7:4], select UART with SC1_MODE Serial interface, clock (internal pull-down) GPIO3 GPIO4 GPIO5 GPIO6 GPIO7 GPIO8 TXD RXD SIF_CLK 22 23 24 25 26 27 28 29 30 Computime Ltd. All rights reserved Confidential Page 7 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Block Diagram Circuit Description The module contains an IEEE 802.15.4 compliant SoC RF transceiver, internal memory, high speed oscillator, RC oscillator and an external 32 kHz oscillator. The module is intended to run the EmberZNet ZigBee software or other ZigBee network implementation, depending on the specific version. The application software together with the ZigBee protocol software stack can be programmed in Flash memory through the SIF module, using an evaluation board from Ember InSight Desktop. To support user-defined applications, a number of peripherals such as GPIO, UART, SPI, I2C, ADC, and general-purpose timers are integrated. Also, an integrated voltage regulator, power-on-reset circuitry, sleep timer, and low-power sleep modes are available. The deep sleep mode draws less than 1A (need to further verification), allowing products to achieve long battery life. For further details on the SoC transceiver (Ember EM250), please consult the data sheet at http://www.ember.com Computime Ltd. All rights reserved Confidential Page 8 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules SIF Module Programming and Debug Interface SIF is a synchronous serial interface developed by Cambridge Consultants Ltd. It is the primary programming and debug interface of the CT-EM250. The SIF module allows external devices to read and write memory-mapped registers in real-time without changing the functionality or timing of the XAP2b core. The SIF interface provides the following:
IC production test (especially analog)
PCB production test
XAP2b code development
Product control and characterization The pins are:
SIF_LOADB
SIF_CLK
SIF_MOSI
SIF_MISO The maximum serial shift speed for the SIF interface is 48MHz. SIF interface accesses can be initiated even when the chip is in idle and deep sleep modes. An edge on SIF_LOADB wakes the chip to allow SIF cycles. Power Management The CT-EM250 supports three different power modes: processor ACTIVE, processor IDLE, and DEEP SLEEP. The IDLE power mode stops code execution of the XAP2b until any interrupt occurs or an external SIF wakeup command is seen. All peripherals including the radio continue to operate normally. The DEEP SLEEP power mode powers off most of the module but leaves the critical chip functions, such as the GPIO pads and RAM powered by the High Voltage Supply
(VDD_PADS). The module can be woken by configuring the sleep timer to generate an interrupt after a period of time, using an external interrupt, or with the SIF interface. Activity on a serial interface may also be configured to wake up the module, though actual reception of data is not re-enabled until the module has finished waking up. Depending on the speed of the serial data, it is possible to finish waking up in the middle of a byte. Care must be taken to reset the serial interface between bytes and discard any garbage data before the rest. Another condition for wakeup is general activity on GPIO pins. Computime Ltd. All rights reserved Confidential Page 9 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules RF Frequency, Output Power Levels and Data Rates The following table shows the RF channels as defined by the IEEE 802.15.4 The output power level can be configured in the range -32 to 5 dBm. The RF transceiver uses direct sequence spread spectrum (DSSS) with a raw data rate of 250 kbit/s. The modulation format is Offset Quadrature Phase Shift Keying (O-QPSK). It is robust even under noisy environments when sharing the same frequency band with other applications. The use of RF frequencies and maximum allowed RF power should according to different national regulations. The CT-EM250 is complying with the applicable regulations for the world wide 2.4GHz ISM band.
[Subject to final approval: Specifically it complies with the European Union R&TTE directive meeting EN 300 328 and EN300 440 class 2. It also meets the FCC CFR47 Part15 regulations for use in the US and the ARIB T-66 for use in Japan.]
Computime Ltd. All rights reserved Confidential Page 10 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Antenna Design Considerations CT-EM250 provides an integrated antenna. The design should be effective for many applications requiring a compact solution containing all the critical RF parts within the module. Applications requiring better range may consider an external antenna or possibly even an external booster circuit (power amplifier). The range testing using the integrated antenna shows a typical distance of 100 m outdoor line-of-sight (LOS). If the application is used indoor, the range will be around 10 to 30 m, depending on structure and building materials. The module with antenna is matched for use in the 2.4 GHz band. Due to the dielectric ceramic material the antenna is shorter than a normal quarter wave antenna. However, it can still provide high radiation efficiency (typical 1 dBi). The radiating part of the antenna is located on one side of the PCB. The radiation pattern from the antenna is shown in figure 2. The maximum radiation is in the plane normal to the length axis of the antenna. For best possible omni-directional radiation the module should be oriented so that the antenna is vertical. In order to achieve best range the transmitting and receiving antenna should be oriented the same way with same polarity. Indoors reflections of the radio waves will affect the range. Figure 2 : Integrated chip antenna radiation pattern at different orientations Computime Ltd. All rights reserved Confidential Page 11 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules The antenna should be kept away (> 10mm) from metallic or other conductive and dielectric materials, and should never be used inside a metallic enclosure. Compared to lower frequencies, operation at 2.4GHz usually has a shorter LOS. However, the ZigBee mesh network topology provides a more flexible and reliable network topology to end users. The farther end device can easily be reached over a mesh network through other full function (routing) devices. Reflections from walls and other objects may give multi-path fading resulting in dead-zones. With mesh network, other nodes in the network can reach devices in dead-zones. Furthermore, in the case of any failure of a single node, the system can easily reroute to other paths. The mesh network is therefore highly recommended for increased reliability and extended coverage. In applications where the module must be placed in a metallic enclosure, an external antenna must be used. The external antenna must match to 50 Ohm. A PCB antenna can be made as a copper track where the ground plane is removed on the back side. The rest of the PCB board should have a ground plane as large as possible, preferably as large (in one dimension) as the antenna itself, to make it act as a reflector mirror to the antenna. A quarter-wavelength antenna on a PCB must be shorter than the wire antenna due to the influence of the dielectric material of the PCB. The length reduction depends on the PCB thickness and material, as well as how close to the edge of the board the antenna is placed. Typical reduction is to 75-90 %
but specific results may vary. The length of a quarter-wave antenna is given in the table below. Frequency
( MHZ ) Length of whip antenna
( cm ) Length of PCB track
( cm ) 2.9 2450 If, for space reasons, the track is made even shorter than the resonating quarter of wavelength, the antenna should be matched to 50 ohms using a series inductor and a shunt capacitor. 2.2---2.7 Computime Ltd. All rights reserved Confidential Page 12 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules PCB Layout Recommendations For recommended layout pads for the module, please reference Mechanical Dimensions. The area underneath the module should be covered with solder resist in order to prevent short circuiting the test pads on the back side of the module. A solid ground plane is preferred. Unconnected pins should be soldered to the pads, and the pads should be left floating. For the module with integrated antenna, the RF pad can be soldered, but the pad should not be connected further. The two ground pads (pin10 and pin12 should be grounded for all variants.) When using the onboard chip antenna, careful attention is required to the layout of the PCB where the module is mounted. In Figure 3 a mother PCB is shown with a recommended placement of the module. Figure 3 A recommended placement of the module on a mother PCB (Shaded area is ground-plane on mother PCB) FCC Approvals The CT-EM2503 has been designed to meet all national regulations for World-wide use. Using the integrated antenna it conforms to FCC CFR 47 Part 15 (USA). This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any including interference that may cause undesired operation. The device CT-EM2503 carries FCC authorization and is marked with the FCC ID Number. Whilst any device into which this authorized module is installed will not interference received, Computime Ltd. All rights reserved Confidential Page 13 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules normally be required to obtain FCC authorization, this does not preclude the possibility that some other form of authorization or testing may be required for the finished device. When the CT-EM2503 module is integrated inside another device/product, then the outside surface of that device/product must display a label referring to the enclosed module. This exterior label can use wording such as Contains Transmitter Module FCC ID: DI2CT-EM2503 or Contains FCC ID: DI2CT-EM2503 although any similar wording that expresses the same meaning may be used. FCC statement Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
Reorient or relocate the receiving antenna. Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. Consult the dealer or an experienced radio/TV technician for help. Operating description 1. Power-On, the module stand by TX mode, transmit the continued single signal, and all lamp turn off. Push switch S1, the green lamp turn on, the module transmit the modulated signal. Push switch S1 again, the green lamp turn of , the module stand by RX mode, 2. Power-On, The module work at Ch11 automated. Push switch S2, the red lamp turn on, and the worked channel of module turn to Ch12, Push switch S2 again, the red lamp turn off, the worked channel of module turn to Ch13,..,when the worked channel of module is Ch26, Push switch S2, the worked channel of module turn to Ch11.and so cycle ,etc. Computime Ltd. All rights reserved Confidential Page 14 of 15 CT-EM250 ZigBee-Ready RF Transceiver Modules Mechanical Dimensions CT-EM2500 Figure 4 Mechanical Dimensions of CT-EM2500 and CT-EM2501 modules CT-EM2501/2/3 Ordering Information Ordering Number Part Description ZigBee-ready RF module, 128 KB Flash , external antenna ZigBee-ready RF module, 128 KB Flash, integrated antenna ZigBee-ready RF module, 128 KB Flash, integrated meander line antenna ZigBee-ready RF module, 128 KB Flash, integrated antenna FCC approved CT-EM2500 CT-EM2501 CT-EM2502 CT-EM2503 Document Revision History Document Revision 1.0 change Draft Computime Ltd. All rights reserved Confidential Page 15 of 15