PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter FEATURES APPLICATIONS • • • • • • • • • • • • • • • • • • • True single chip FSK/ASK transmitter in a small 8-pin package Adjustable output power up to +10dBm FSK data rate up to 50kbits/s Very few external components On-chip frequency synthesiser gives improved frequency stability compared to SAW solutions Wide power supply range: 2.4 to 3.6 V Low supply current, typical 9mA @ -10dBm output power Power Down and Clock modes makes power saving easy Reference Clock output pin for microcontroller Automatic Meter Reading Keyless entry Wireless data communication Alarm and security systems Home Automation Remote control Surveillance Automotive Telemetry Toys GENERAL DESCRIPTION nRF902 is a single-chip transmitter for the 868 MHz ISM band, designed to comply with the ETSI specification I-ETS 300 220. Using nRF902 both FSK and ASK modulation is possible. The transmitter consists of a fully integrated frequency synthesiser, a power amplifier, a crystal oscillator and a modulator. Few external components are required: a 13.567 MHz crystal, two resistors and some decoupling capacitors. Due to the use of the crystal-oscillator stabilised frequency synthesiser, frequency drift is much lower than in comparable SAW-resonator based solutions. Output power is easily programmable by use of an external resistor. Current consumption is very low, only 9 mA at an output power of –10dBm. Built-in Clock and Power Down modes makes power saving and duty-cycling easily realisable. QUICK REFERENCE DATA Parameter Value Unit 2.4 10 50 10 9 200 <10 V dBm kbit/s kbit/s mA µA nΑ Minimum supply voltage Maximum output power Maximum FSK data rate Maximum ASK data rate Supply current FSK transmitter @ -10dBm output power Supply current in Clock mode Supply current in Power Down mode Table 1. nRF902 quick reference data Main office: Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 Page 1 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter BLOCK DIAGRAM Crystal Oscillator Clock Divider xtal 1 /8 FSK XO8 Frequency synthesizer Phase Detector Loop Filter VCO Power A m p lifier ant1 ant2 Prescaler 1/64 REXT Figure 1. nRF902 block diagram PIN FUNCTIONS Pin Name Pin function Description 1 2 3 4 5 6 7 8 xtal REXT XO8 VDD FSK ant2 ant1 VSS Input Input Output Input Input Power/Output Power/Output Power Crystal pin / Power Up Power adjust / Clock Mode / ASK modulation digital input Reference Clock Output (Crystal Frequency / 8) Positive Supply (2.4 - 3.6V) Digital Data Input Antenna output 1 Antenna output 2 Ground (0V) Table 2. nRF902 pin functions PIN ASSIGNMENT 8 VSS 2 7 ant1 XO8 3 6 ant2 VDD 4 5 FSK xtal 1 REXT nRF902 Figure 2. nRF902 pin assignment Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 2 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter ELECTRICAL SPECIFICATIONS Conditions: VDD = +3V, VSS = 0V, TA = - 40ºC to + 85ºC Symbol Parameter (condition) fXTAL VDD Tamb PRF IDD IDD Operating conditions Transmit frequency Crystal frequency Supply voltage Operating temperature Maximum Output Power Supply current CLOCK Mode Supply current POWER DOWN Mode ∆f RFSK IDD IDD FSK modulation Frequency deviation FSK data rate Supply current @ 10dBm output power Supply current @ -10dBm output power RASK PRF1 PRF0 IDD IDD ASK modulation ASK data rate Transmitted power at data = ‘1’ Transmitted power at data = ‘0’ Supply current @ 10dBm output power Supply current @ -50dBm output power VIH VIL VOH VOL FSK input pin HIGH level input voltage LOW level input voltage HIGH level output voltage LOW level output voltage fTX Notes Min. 1) 1) 868 13.563 2.4 - 40 3) 2) 10 3) 3) Typ. Max. Units 200 10 870 13.593 3.6 + 85 10 300 100 MHz MHz V °C dBm µA nA 30 9 30 50 37 17 kHz kbit/s mA mA 30 200 10 10 -50 37 300 kbit/s dBm dBm mA uA VDD 0.3 VDD 0.3 V V V V 20 0 3) 3) VDD - 0.5 Vss VDD - 0.5 Vss NOTES: 1) The crystal frequency may be altered to produce any desired frequency within the 868MHz to 870MHz band. 2) Measured with no load on XO8 output pin. 3) Antenna load impedance = 400 Ω. Table 3. nRF902 electrical specifications Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 3 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter PACKAGE OUTLINE nRF902, uses the SOIC 8 package. Dimensions are in mm. 8 7 6 5 E H 1 2 3 4 D α A1 A L e Package Type SOIC 8 b Min Max D 4.80 4.98 E 3.81 3.99 H 5.84 6.20 A 1.55 1.73 A1 0.127 0.250 e 1.27 b 0.35 0.49 L 0.41 0.89 Copl. 0.25 α 0° 8° Figure 3. Package outline. Absolute Maximum Ratings Supply voltages VDD ............................. - 0.3V to + 6V VSS ................................................ 0V Input voltage VI ...................... - 0.3V to VDD + 0.3V Total Power Dissipation PD (TA=85°C)........................... 220mW Temperatures Operating Temperature…. - 40°C to + 85°C Storage Temperature…... - 40°C to + 125°C Output voltage VO ..................... - 0.3V to VDD + 0.3V Note: Stress exceeding one or more of the limiting values may cause permanent damage to the device. ATTENTION! Electrostatic Sensitive Device Observe Precaution for handling. Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 4 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter IMPORTANT TIMING DATA Timing information The timing information for the different operations is summarised in Table 4. (TX is Transmit mode, Clk is Clock mode, Pwr_Dn is Power Down Mode.) Change of Mode Pwr_Dn è TX Clk è TX Max Delay 2ms 30us Table 4 Switching times for nRF902 Switching between Power Down Mode and Transmit-mode. The maximum time from Power Down mode until the synthesised frequency is stable and data can be transmitted is seen in Figure 4. VDD xtal FSK 2ms ms 0 2 4 Figure 4. Timing diagram when going from Power Down mode to Transmit-mode Switching between Clock Mode and Transmit-mode. The maximum time from Clock mode until the synthesised frequency is stable and data can be transmitted is seen in Figure 5. VDD REXT FSK 30us us 0 30 Figure 5. Timing diagram when going from Clock mode to Transmit-mode Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 5 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter APPLICATION INFORMATION FSK Transmit mode FSK modulation is realised by feeding the modulating data to the digital FSK input pin (see Figure 6). X1 13.567MHz R1 VDD xtal 1 R2 VDD REXT Clock Output XO8 VDD VDD 8 nRF902 7 2 6 3 5 4 VSS ant1 ant2 Matching Network/ Antenna Data Input FSK C 2 C 1 Figure 6. FSK transmitter in FSK Transmit mode In applications where high data rate and low spectrum bandwidth is required an external varactor may be used to modulate the crystal. For optimum bandwidth usage a low pass filter should be used to shape the input bit stream, (see Figure 7). Data Input X1 13.567MHz R1 VDD xtal nRF902 R2 VDD REXT Clock Output XO8 VDD VDD C1 8 1 2 7 3 6 4 5 VSS ant1 Matching Network/ Antenna ant2 FSK C2 Figure 7. FSK transmitter in FSK Transmit mode for low spectral bandwidth Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 6 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter ASK modulation. ASK modulation can be realised by using the REXT pin (see Figure 8). When R2 is connected to VDD, the chip transmits a carrier. When the bias resistor is connected to VSS then the internal output power amplifier is turned off. These two situations represent logic ‘1’ and logic ‘0’ in an ASK system. When ASK modulation is used, the FSK pin must be connected to VDD. X1 13.567MHz R1 VDD xtal Data Input 1 R2 REXT Clock Output XO8 VDD VDD C1 8 nRF902 7 2 6 3 5 4 VSS ant1 Matching Network/ Antenna ant2 VDD FSK C2 Figure 8. FSK transmitter in ASK Transmit mode Antenna output The “ant” output pins provide a balanced RF output to the antenna. The pins must have a DC path to VDD, either via a RF choke or via the centre point in a loop antenna. The load impedance seen between the ant1/ant2 outputs should be in the range 200700Ω. A load impedance of 400Ω is recommended if maximum output power (10dBm) is needed. Lower load impedance (for instance 50 Ω) can be obtained by fitting a simple matching network or a RF transformer (balun). The 50 Ω load can also be connected directly between the ant1/ant2 pins, but this will result in higher current consumption for a given output power to the antenna. Note: Application notes of antenna layout solutions with matching networks will soon be available on our website: http://www.nvlsi.no. Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 7 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter Power Down mode Power Down mode is used to achieve very low current consumption. Effectively the chip is disabled with minimal leakage current consumption, typically less than 10nA. Operating in this mode when not transmitting data, i.e. low duty cycle systems can significantly increase battery lifetime. The resistor R1 connected from the crystal pin towards VDD supplies the crystal oscillator with bias current (see Figure 9). When this resistor is connected to VSS or left open, the chip enters Power Down mode. As shown in Figure 9 the resistor R1 is connected to the “Power Down” terminal, this can be controlled by a micro-controller, hence eliminating the need to switch off the power supply to the chip when not transmitting. Start-up time when switching from Power Down mode to Transmit mode is approximately 2 ms. X1 13.567MHz R1 Power Down xtal 1 R2 VDD REXT Clock Output XO8 VDD VDD C1 8 nRF902 7 2 6 3 5 4 VSS ant1 Matching Network/ Antenna ant2 Data Input FSK C2 Figure 9. FSK transmitter in Power Down mode Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 8 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter Clock mode Clock mode is available so that an external microprocessor may have a reference signal without the cost of a second crystal. In Clock mode, the crystal oscillator and reference clock outputs are operating, while the rest of the transmitter is disabled. The reference signal from the internal crystal oscillator is divided by 8 by use of a prescaler, this signal is available at the XO8 pin. Clock mode may be set by connecting the power adjusting resistor R2 to ground or by leaving it open (see Figure 10). Current consumption in Clock mode is typically 200 µA when no load is applied at the XO8 clock output pin. If a capacitive load is applied at the XO8 output, then current consumption in Clock mode will increase. Start-up time when switching between Clock mode and Transmit mode is extremely fast, typically 30µs. X1 13.567MHz R1 VDD xtal nRF902 R2 REXT Clock Output XO8 VDD VDD C1 8 1 7 2 6 3 5 4 VSS ant1 Matching Network/ Antenna ant2 Data Input FSK C2 Figure 10. FSK transmitter in Clock mode XO8 Clock Output Pin Capacitance The frequency of the clock signal is 1/8th of the crystal frequency i.e. a crystal frequency of 13.567 MHz will result in an output clock frequency of 1.695 MHz. The XO8 output signal will be present in Transmit mode and Clock mode. In Power Down mode the XO8 signal will be a logic “0”. The capacitive load at the XO8 pin will affect current consumption in Clock mode. If the pin is left open the current consumption will typically be 200uA. Adding a capacitive load, such as microcontroller load [CML] to the XO8 pin will result in an increase in the current consumption, the increase ∆I is given as: ∆I = fXO8 ⋅VDD⋅ CML Example With a capacitive load of CML = 5pF, using VDD=3.0 V and a 13.567 MHz crystal, the current increase ∆I becomes : ∆I = fXO8 ⋅VDD⋅ CML = ((13 .567 MHz) / 8) ⋅ 3.0 V ⋅ 5 pF = 25 uA. The typical current consumption will increase to 225uA when adding CML=5 pF. Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 9 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter Crystal Specification Modulation is achieved by pulling of the crystal capacitance. As such to achieve correct frequency deviation (20kHz) and frequency of operation as specified in Table 3 the crystal must meet the following specification: Co ≤ 3 pF ESR ≤ 50 ohm . C L = 12 pF Crystal parallel equivalent capacitor Crystal equivalent series resistor Crystal load capacitor Output Power adjustment A bias resistor R2 (see Figure 6) should be connected from the REXT pin to the positive power supply VDD. The value of this resistor determines the output power level. See table 5 for choice of R2 value. Power setting resistor R2 22kΩ 82kΩ 180kΩ RF output power 10dBm 0dBm -10dBm DC current consumption 30mA 15mA 9mA Conditions: VDD = 3.0V, VSS = 0V, TA = 27ºC, Load impedance = 400 Ω. Table 5. RF output power setting for the nRF902. Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 10 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter DEFINITIONS Data sheet status Objective product specification Preliminary product specification Product specification This datasheet contains target specifications for product development. This datasheet contains preliminary data; supplementary data may be published from Nordic VLSI ASA later. This datasheet contains final product specifications. Nordic VLSI ASA reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. Limiting values Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Specifications sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information Where application information is given, it is advisory and does not form part of the specification. Table 6. Definitions. Nordic VLSI ASA reserves the right to make changes without further notice to the product to improve reliability, function or design. Nordic VLSI does not assume any liability arising out of the application or use of any product or circuits described herein. LIFE SUPPORT APPLICATIONS These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Nordic VLSI ASA customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Nordic VLSI ASA for any damages resulting from such improper use or sale. Preliminary specification: Revision Date: 06/04/2000. Datasheet order code: 060400-nRF902. All rights reserved ®. Reproduction in whole or in part is prohibited without the prior written permission of the copyright holder. Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 11 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter YOUR NOTES Nordic VLSI ASA Revision: 1.0 - Vestre Rosten 81, N-7075 Tiller, Norway Page 12 of 13 - Phone +4772898900 - Fax +4772898989 April 2000 PRELIMINARY PRODUCT SPECIFICATION nRF902 Single chip 868 MHz Transmitter Nordic VLSI ASA – World Wide Distributors For Your nearest dealer, please see http://www.nvlsi.no Main Office: Vestre Rosten 81, N-7075 Tiller, Norway Phone: +47 72 89 89 00, Fax: +47 72 89 89 89 E-mail: [email protected] Visit the Nordic VLSI ASA website at http://www.nvlsi.no Revision 1.0 April 2000