NRF401

PRODUCT SPECIFICATION 433MHz Single Chip RF Transceiver FEATURES • • • • • • • • • True single chip FSK transceiver Few external components required No set up or configuration No coding of data required 20kbit/s data rate 2 channels Wide supply range Very low power consumption Standby mode nRF401 APPLICATIONS • • • • • • • • • Alarm and Security Systems Automatic Meter Reading (AMR) Home Automation Remote Control Surveillance Automotive Telemetry Toys Wireless Communication GENERAL DESCRIPTION nRF401 is a true single chip UHF transceiver designed to operate in the 433MHz ISM (Industrial, Scientific and Medical) frequency band. It features Frequency Shift Keying (FSK) modulation and demodulation capability. nRF401 operates at bit rates up to 20kbit/s. Transmit power can be adjusted to a maximum of 10dBm. Antenna interface is differential and suited for low cost PCB antennas. nRF401 features a standby mode which makes power saving easy and efficient. nRF401 operates from a single +3-5V DC supply. As a primary application, nRF401 is intended for UHF radio equipment in compliance with the European Telecommunication Standard Institute (ETSI) specification EN 300 220-1 V1.2.1. QUICK REFERENCE DATA Parameter Frequency, Channel#1/Channel#2 Modulation Frequency deviation Max. RF output power @ 400Ω, 3V Sensitivity @ 400Ω, BR=20 kbit/s, BER 2.7 V) for at least 5ms, see Figure 6(b). If an external reference oscillator is used, the receiver may receive data (DOUT) after 3ms. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 6 of 18 Phone +4772898900 Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver APPLICATION INFORMATION Antenna input/output The ANT1 and ANT2 pins provide RF input to the LNA (Low Noise Amplifier) when nRF401 is in receive mode, and RF output from the PA (Power Amplifier) when nRF401 is in transmit mode. The antenna connection to nRF401 is differential and the recommended load impedance at the antenna port is 400Ω . Figure 12 shows a typical application schematic with a differential loop antenna on a Printed Circuit Board (PCB). The output stage (PA) consists of two open collector transistors in a differential pair configuration. VDD to the PA must be supplied through the collector load. When connecting a differential loop antenna to the ANT1/ANT2 pins, VDD should be supplied through the centre of the loop antenna as shown in Figure 12. A single ended antenna or 50Ω test instrument may be connected to nRF401 by using a differential to single ended matching network (BALUN) as shown in Figure 7. 180nH 18nH ANT1 470pF RF in/out 50 ohm nRF401 1.8pF VDD ANT2 18nH Figure 7. Connection of nRF401 to single ended antenna by using a differential to single ended matching network. The 180nH inductor to VDD in Figure 7, need to have a Self-Resonance Frequency (SRF) above 433 MHz to be effective. Suitable inductors are listed in Table 6. Vendors Stetco Coilcraft muRata WWW address http://www.stetco.com http://www.coilcraft.com http://www.murata.com Part. no., 180 nH inductors, 0603 size 0603G181KTE 0603CS-R18XJBC LQW1608AR18J00 Table 6. Vendors and part. no. for suitable 180nH inductors. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 7 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver An additional notch filter (L and C) at the 50Ω RF input/output may be necessary dependent on the application requirements (see application note nAN400-05). A single ended antenna may also be connected to nRF401 using an 8:1 impedance RF transformer. The RF transformer must have a centre tap at the primary side for VDD supply. RF output power The external bias resistor R3 connected between the RF_PWR pin and VSS sets the output power. The RF output power may be set to levels up to +10dBm. In Figure 8 the output power is plotted for power levels down to, but not limited to, -8.5dBm for a differential load of 400Ω. DC power supply current versus external bias resistor value is shown in Figure 9. RF Output Power 10 8 6 4 2 0 -2 -4 -6 150 -8 -10 0 20 40 60 80 100 120 140 160 180 200 Resistor Value [kΩ] 180 22 27 33 39 47 56 68 82 100 120 Figure 8. RF output power vs. external power setting resistor (R3) for nRF401. Total Chip Current 30,0 22 27 20,0 33 39 15,0 47 56 68 10,0 82 100 120 25,0 Current Consumption [mA] 150 180 5,0 0,0 0 20 40 60 80 100 120 140 160 180 200 Resistor Value [kΩ ] Figure 9. Total chip current consumption vs. external power setting resistor (R3) for nRF401. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 8 of 18 Phone +4772898900 Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver PLL loop filter The synthesiser loop filter is an external, single-ended second order lag-lead filter. The recommended filter component values are: C3 = 820 pF, C4 =15 nF, and R2 = 4.7 kΩ, see Figure 12. VCO inductor An external 22nH inductor connected between the VCO1 and VCO2 pins is required for the on-chip voltage controlled oscillator (VCO). This inductor should be a high quality chip inductor, Q > 45 @ 433 MHz, with a maximum tolerance of ± 2%. The following 22 nH inductors (0603) are suitable for use with nRF401. Vendors Pulse Coilcraft muRata Stetco KOA WWW address http://www.pulseeng.com http://www.coilcraft.com http://www.murata.com http://www.stetco.com http://www.koaspeer.com Part. no., 22 nH inductors, 0603 size PE-0603CD220GTT 0603CS-22NXGBC LQW1608A22NG00 0603G220GTE KQ0603TE22NG Table 7. Vendors and part no. for suitable 22nH inductors. See page 11 and 12 for PCB layout guidelines regarding placement of the inductor. Crystal specification To achieve an active crystal oscillator (XOSC) with low power consumption, certain requirements apply for crystal loss and capacitive load. The crystal specification is: f= 4.0000 MHz Co ≤ 5 pF ESR ≤150 ohm . C L ≤ 14 pF Crystal parallel resonant frequency Crystal parallel equivalent capacitance Crystal equivalent series resistance Total crystal load capacitance, including capacitance in PCB layout. For the crystal oscillator shown in Figure 10 the load capacitance becomes: CL = C1´⋅ C 2´ , C1´ + C 2 ´ Where C1´ = C1 + CPCB1 and C2´ = C2 + CPCB2 C1 and C2 are 0603 SMD capacitors as shown in the application schematic, see Figure 12 and Table 9. CPCB1 and CPCB2 are the layout parasitic capacitance on the circuit board. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 9 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver Crystal oscillator Internal R External components Crystal equivalent Co ESR Cs L Crystal C1 C2 Figure 10. Crystal oscillator and crystal equivalent. Sharing a reference crystal with a micro-controller Figure 11 shows circuit diagram of a typical application where nRF401 and a micro controller share the reference crystal. XC1 1.0M R micro controller X1 X2 nRF401 C XC2 5.6pF C1 22pF 4.0 MHz C2 22pF Figure 11. nRF401 and a micro-controller sharing the reference crystal. The crystal reference line from the micro-controller should not be routed close to full swing digital data or control signals. Transmit/receive mode selection TXEN is a digital input for selection of transmit or receive mode. TXEN = “1” selects transmit mode. TXEN = “0” selects receive mode. Channel#1 / Channel#2 selection CS is a digital input for selection of either channel#1 (f1=433.92MHz) or channel#2 (f2=434.33MHz). CS = “0” selects channel#1. CS = “1” selects channel#2. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 10 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver TXEN 0 0 1 1 X Input CS 0 1 0 1 X PWR_UP 1 1 1 1 0 Response Channel # Mode 1 RX 2 RX 1 TX 2 TX -Standby Table 8. Required setting for standby and channel selection in RX and TX. DIN (data input) and DOUT (data output) The DIN pin is the input to the digital modulator of the transmitter. The input signal to this pin should be standard CMOS logic level at data rates up to 20 kbit/s. No coding of data is required. DIN = “1” → f = f0 + ∆f DIN = “0” → f = f0 - ∆f The demodulated digital output data appear at the DOUT pin at standard CMOS logic levels. f0 + ∆f → DOUT=“1”, f0 - ∆f → DOUT=“0”. Power up PWR_UP is a digital input for selection of normal operating mode or standby mode. PWR_UP = “1” selects normal operating mode. PWR_UP = “0” selects standby mode. Frequency difference between transmitter and receiver For optimum performance, the total frequency difference between transmitter and receiver should not exceed 70 ppm (30 kHz). This yields a crystal stability requirement of ±35 ppm for the transmitter and receiver. Frequency difference exceeding this will result in a -12dB/octave drop in receiver sensitivity. The functional frequency window of the transmission link is typically 450 ppm (200 kHz). Example: A crystal with ±20 ppm frequency tolerance and ±25 ppm frequency stability over the operating temperature has a worst case frequency difference of ±45 ppm. If the transmitter and receiver operate in different temperature environments, the resulting worst-case frequency difference may be as high as 90 ppm. Resulting drop in sensitivity due to the extra 20 ppm, is then approx. 5dB. PCB layout and decoupling guidelines A well-designed PCB is necessary to achieve good RF performance. A PCB with a minimum of two layers including a ground plane is recommended for optimum performance. The nRF401 DC supply voltage should be decoupled as close as possible to the VDD pins with high performance RF capacitors, see Table 9. It is preferable to mount a Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 11 of 18 Phone +4772898900 Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver large surface mount capacitor (e.g. 2.2 µF ceramic) in parallel with the smaller value capacitors. The nRF401 supply voltage should be filtered and routed separately from the supply voltages of any digital circuitry. Long power supply lines on the PCB should be avoided. All device grounds, VDD connections and VDD bypass capacitors must be connected as close as possible to the nRF401 IC. For a PCB with a topside RF ground plane, the VSS pins should be connected directly to the ground plane. For a PCB with a bottom ground plane, the best technique is to have via holes in or close to the VSS pads. Full swing digital data or control signals should not be routed close to the PLL loop filter components or the external VCO inductor. The VCO inductor placement is important. The optimum placement of the VCO inductor gives a PLL loop filter voltage of 1.1 ±0.2 V, which can be measured at FILT1 (pin4). For a 0603 size inductor the length between the centre of the VCO1/VCO2 pad and the centre of the inductor pad should be 5.4 mm, see Figure 13 (c) (layout, top view), for a 2 layer, 1.6 mm thick FR4 PCB. PCB layout example Figure 13 shows a PCB layout example for the application schematic in Figure 12. A double-sided FR-4 board of 1.6mm thickness is used. This PCB has a continuous ground plane on the bottom layer. Additionally, there are ground areas on the component side of the board to ensure sufficient grounding of critical components. A large number of via holes connect the top layer ground areas to the bottom layer ground plane. There is no ground plane beneath the antenna. For more layout information, please refer to application note nAN400-05, “nRF401 RF and antenna layout. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 12 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver APPLICATION SCHEMATIC +3V R1 C5 2.2uF 1206 C1 22pF 0603 1M 0603 X1 4.000 MHz C2 22pF 0603 REFERENCE U1 1 2 3 4 5 6 7 8 9 10 XC1 VDD VSS FILT1 VCO1 VCO2 VSS VDD DIN DOUT XC2 TXEN PWR_UP VSS ANT1 ANT2 VSS VDD CS RF_PWR 20 19 18 17 16 15 14 13 12 11 TXEN PWR_UP C10 3.3pF 0603 C11 5.6pF 0603 C4 15nF 0603 C3 820pF 0603 L1 22nH 0603 R2 4.7K 0603 C6 100nF 0603 C7 1nF 0603 DIN DOUT R4 18K aaaaaaaa 0603 CS C9 100pF 0603 C8 100pF 0603 nRF401 433MHz Single Chip RF Transceiver SSOIC20 R3 22K 0603 PLL FILTER J1 Loop antenna 25x15mm Q=55 Figure 12. nRF401 application schematic. Component C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 L1 R1 R2 R3 R4 X1 Description NP0 ceramic chip capacitor, (Crystal oscillator) NP0 ceramic chip capacitor, (Crystal oscillator) X7R ceramic chip capacitor, (PLL loop filter) X7R ceramic chip capacitor, (PLL loop filter) X7R ceramic chip capacitor, (Supply decoupling) X7R ceramic chip capacitor, (Supply decoupling) X7R ceramic chip capacitor, (Supply decoupling) NP0 ceramic chip capacitor, (Supply decoupling) NP0 ceramic chip capacitor, (Supply decoupling) NP0 ceramic chip capacitor, (Antenna tuning) NP0 ceramic chip capacitor, (Antenna tuning) VCO inductor, Q>45 @ 433 MHz 0.1W chip resistor, (Crystal oscillator) 0.1W chip resistor, (PLL loop filter) 0.1W chip resistor, (Transmitter power setting) 0.1W chip resistor, (Antenna Q reduction) Crystal Size 0603 0603 0603 0603 1206 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 - Value 22 22 820 15 2.2 100 1 100 100 3.3 5.6 22 1.0 4.7 22 18 4.000 Tolerance Units pF pF pF nF µF nF nF pF pF pF pF nH MΩ kΩ kΩ kΩ MHz ±0.1 ±0.25 ±2% Table 9. Recommended External Components. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 13 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver a) Top silk screen b) Bottom silk screen c) Top view d) Bottom view Figure 13. PCB layout (example) for nRF401 with loop antenna. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 14 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver 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 10. 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. Product specification: Revision Date: 26.05.2000. Datasheet order code: 260500nRF401 All rights reserved ®. Reproduction in whole or in part is prohibited without the prior written permission of the copyright holder. Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 15 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver YOUR NOTES Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 16 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver YOUR NOTES Nordic VLSI ASA Revision: 1.5 Vestre Rosten 81, N-7075 Tiller, Norway Page 17 of 18 Phone +4772898900 - Fax +4772898989 May 2000 PRODUCT SPECIFICATION nRF401 Single Chip RF Transceiver Nordic VLSI - 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: nRF@nvlsi.no Visit the Nordic VLSI ASA website at http://www.nvlsi.no Revision: 1.5 Page 18 of 18 May 2000