View NRF904_1175538.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

application note nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 NRF904 rf and antenna layout *hqhudo gerber files for rf layouts have been made for nordic vlsis q5) single chip 915mhz rf transmitter [1]. a loop antenna for 915mhz has also been made available. the gerber files for each layout are compressed into the zip archive format. the zip archive files includes a file named uhdgphzul that must be read before importing the gerber files into the pcb editor. all described layouts should be fabricated on standard 1.6mm double-sided fr4 printed circuit board. 5)od\rxwiruq5) the rf layouts include all necessary circuitry to design the radio frequency part of a short range communication system based on q5) . the transmitter data and control lines din, xo8, pwr_down, and clock/ask, are available at the perimeter of the rf layout and should be connected to the digital part of a customers application. +3v and gnd are also available at the perimeter of the rf layout. the +3v for the rf part of the application circuit should be filtered separately from the supply voltages of any digital circuitry. star routing is strictly recommended from the +3v supply source to the rf, digital or other parts of the application circuit. all rf layouts presented below are equal except for the antenna connection circuitry. solutions for differential connection to loop antenna and single ended connection to 50 w antenna are presented. 'liihuhqwldofrqqhfwlrqwrorrsdqwhqqd figure 1 shows the schematics for rf layout with differential connection to a loop antenna. the pcb layout is shown in figure 2. the loop antenna layout described in chapter 3 can easily be placed together with this rf layout. the connection points numbered 1, 2 and 3 on the loop antenna layout must be connected exactly to the corresponding connection points numbered 1, 2 and 3 on the rf layout. the gerber files zip archive filename is 3&%bq5)bglii]ls . the recommended external components are as given in table 1. q$1
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 &rpsrqhqw 'hvfulswlrq 6l]h 9doxh 7rohudqfh 8qlwv c1 np0 ceramic chip capacitor (rext pin decoupling) 0603 33 pf c2 x7r ceramic chip capacitor (rext pin decoupling) 0603 4.7 nf c3 x7r ceramic chip capacitor (supply decoupling) 0603 4.7 nf c4 np0 ceramic chip capacitor (supply decoupling) 0603 33 pf c5 np0 ceramic chip capacitor (supply decoupling) 0603 33 pf c6 tantalum chip capacitor (supply decoupling) 3216 4.7 m f c7 x7r ceramic chip capacitor (data bit stream filter) 0603 680 pf r1 0.1w chip resistor (crystal oscillator bias) 0603 150 k w r2 0.1w chip resistor (transmitter power setting) 0603 47 1) k w r3 0.1w chip resistor (xo8 output level setting) 0603 15 2) k w r4 0.1w chip resistor (data bit stream filter/frequency deviation setting) 0603 22 3) k w r5 0.1w chip resistor (data bit stream filter/frequency deviation setting) 0603 3.9 4) k w x1 crystal - 14.2992 5) mhz table 1 recommended external components. 1), 2), 3), 4), 5) see [1]. 6lqjohhqghgfrqqhfwlrqwr : dqwhqqde\xvlqjdgliihuhqwldowrvlqjoh hqghgpdwfklqjqhwzrun figure 3 shows the schematics for rf layout with single ended connection to 50 w antenna by using a differential to single ended matching network. the pcb layout is shown in figure 4. the antenna connection point should be as close as possible to the output of the matching network. if this is not possible of practical reasons, the pcb track between the output of the matching network and the antenna connection should be carried out as a 50 w microstrip line. in such a case, the length of the microstrip line is limited to a few centimetres. for a standard fr4 printed circuit board with 1.54mm substrate thickness and relative dielectric constant e r ? 4.25 at 915mhz, the width of the microstrip line should be 3mm. the gerber files zip archive filename is 3&%bq5)bvlqjohbqhwz]ls . the recommended external components are as given in table 1, with addition of the components in the differential to single ended matching network as given in table 2.
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 &rpsrqhqw 'hvfulswlrq 6l]h 9doxh 7rohudqfh 8qlwv c8 np0 ceramic chip capacitor (impedance matching) 0603 3.3 < 0.1 pf c9 np0 ceramic chip capacitor (impedance matching) 0603 3.3 < 0.1 pf r6 0.1w chip resistor (impedance matching) 0603 1 k w l1 chip inductor, srf>915 mhz 6) (impedance matching) 0603 68 5% nh l2 chip inductor, srf>915 mhz 7) (impedance matching) 0603 15 2% nh table 2 recommended components in the differential to single ended matching network 6), 7) see [1].
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 r2 47k 0603 r1 150k 0603 vdd c3 4.7nf 0603 x1 14.2992mhz xtal 1 rext 2 xo8 3 vdd 4 din 5 ant2 6 ant1 7 vss 8 u1 NRF904 915mhz single chip rf transmitter soic 8 c4 33pf 0603 c2 4.7nf 0603 c1 33pf 0603 r5 3.9k 0603 c7 680pf 0603 c5 33pf 0603 aaaaaaa a 1 2 3 loop antenna connection r4 22k 0603 clock/ask xo8 din + c6 4.7uf 3216 r3 15k 0603 aaaaaaaa aaaaaaaa aaaaaaaa pwr_down figure 1. schematics for rf layout with differential connection to a loop antenna top silk screen bottom silk screen top view bottom view figure 2. rf layout with differential connection to a loop antenna
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 r2 47k 0603 r1 150k 0603 vdd c3 4.7nf 0603 x1 14.2992mhz xtal 1 rext 2 xo8 3 vdd 4 din 5 ant2 6 ant1 7 vss 8 u1 NRF904 915mhz single chip rf transm itter soic 8 c4 33pf 0603 c2 4.7nf 0603 c1 33pf 0603 r5 3.9k 0603 c7 680pf 0603 r4 22k 0603 pwr_down clock/ask xo8 din + c6 4.7uf 3216 r3 15k 0603 l2 15nh 0603 l1 68nh 0603 c5 33pf 0603 c9 3.3pf 0603 c8 3.3pf 0603 vdd xxxxx x r6 1k 0603 rf out 50 ohm aaaaaaaa aaaaaaaa aaaaaaaa figure 3. schematics for rf layout with single ended connection to 50 w antenna by using a differential to single ended matching network top silk screen bottom silk screen top view bottom view figure 4. rf layout with single ended connection to 50 w antenna by using a differential to single ended matching network
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 /rrsdqwhqqdod\rxwv a loop antenna with t-match [2] is a good solution for low cost and small size radio modules. a layout solution for a small rectangular loop antenna is described below. figure 5 shows the basic geometry of the designed rectangular loop antenna. c1 a 2 a 1 d/2 c2 r q 1 2 3 d/2 c3 figure 5. geometry of rectangular loop antenna the loop antenna physical parameters are d = loop antenna length [mm] d = loop antenna width [mm] g = feed length [mm] e = width of loop conductor the antenna is tuned to a resonance frequency of 915mhz with chip capacitors & & and & . to keep the variations in antenna gain due to capacitor variations lower than 3db and thus achieve reproducible values of antenna gain in mass production, the total tuning capacitance tolerance should not exceed 5% (that is, 2.5%). according to [2], the antenna should then be designed for a q-value of about 40. for the designed loop antenna, capacitors && and & should have tolerances equal to or better than 0.1pf. the resistor 5 4 controls the 4 -value of the antenna. the loop antenna is tuned to approximately 300 w with a t-match. the width of the loop conductor is 1.524mm (60mil). there is no ground plane beneath the antenna. table 3 shows a summary of the designed loop antenna. & & & /rrs dqwhqqd d [ d >pp@ )hhg ohqjwk g >pp@ 9doxh >s)@ 7rohudqfh >s)@ 9doxh >s)@ 7rohudqfh >s)@ 9doxh >s)@ 7rohudqfh >s)@ 5 4 >n : @ 4 ydoxh =r > : @ 9.5x9.5 13 3.3 0.1 3.9 0.1 6.8 0.1 18 40 300 table 3 summary of the loop antenna 8) thick film chip resistor with resistance tolerance 5% or better.
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 the component values given in table 3 are only valid when the connection points numbered 1, 2 and 3 on the loop antenna layout, as shown in figure 6, are connected exactly to the corresponding connection points numbered 1, 2 and 3 on the rf layout with differential loop antenna connection. the component footprints used in the loop antenna layout are size 0603. the layout of the rest of the communication system may influence the antenna tuning and require measurement of the antenna together with the complete system in order to find the values for c1, c2, c3 and r q for your system. figure 6. loop antenna pcb layout (not actual size) it is recommended that a system should not be designed with a longer communication range than the application requires. estimations on communication range with the antenna presented in this application note and a receiver with a given sensitivity and antenna gain, can be made based on the theory given in [2]. initial communication range tests should be carried out with the lowest rf output power setting that, based on the estimations, satisfies the range requirements. if the achieved communication range does not satisfy the requirements, the rf output power should be increased to the required level. table 4 lists the gerber file zip archive filename for the antenna layout. /rrsdqwhqqd d [ d >pp@ *huehuilohv=lsdufklyhilohqdph 9.5x9.5 loop_9.5x9.5mm_915mhz.zip table 4 gerber files zip archive filenames measured loop antenna gain relative to l /4 dipole antenna mounted on a 40x40cm ground plane is shown in table 5. /rrsdqwhqqd d [ d >pp@ *dlquhodwlyhwr o glsroh dqwhqqd >g%@ 9.5x9.5 -15 table 5 measured loop antenna gain relative to l /4 dipole antenna mounted on a 40x40cm ground plane
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 5hihuhqfhv 1. product specification q5) , single chip 915mhz transmitter, nordic vlsi asa. 2. application note q$1 , small loop antennas, nordic vlsi asa.
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 /,$%,/,7<',6&/$,0(5 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. /,)(6833257$33/,&$7,216 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. application note. revision date : 08.11.2001. application note order code : 081101-nan900-03 all rights reserved ?. reproduction in whole or in part is prohibited without the prior written permission of the copyright holder.
application note q5)5)dqgdqwhqqdod\rxw nordic vlsi asa - vestre rosten 81, n-7075 tiller, norway - phone +47 72 89 89 00 - fax +47 72 89 89 89 revision: 1.1 3djhri november 2001 <285127(6
application note q5)5)dqgdqwhqqdod\rxw revision: 1.1 3djhri november 2001 1ruglf9/6,:ruog:lgh'lvwulexwruv )ru

▲Up To Search▲

Price & Availability of NRF904

	To Download NRF904 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .