Date:2010-08-26 05:30:41 (10 years 1 month ago)
Author:Werner Almesberger
Commit:5b73e8bb75eb8e62b07d2c1adab4e74cf9a97919
Message:Populated load capacitors of the crystal. Started organizing issues in ECNs.

- atrf/ecn/INDEX: ECN index
- atrf/ecn/ecn0001.txt: Adjust balun component values (pending)
- atrf/ecn/ecn0002.txt: Add load capacitors to 16 MHz crystal (C14, C15)
- atrf.sch, atrf/wpan-atrf.brd: changed load capacitors from NC to 12 pF
- atrf/ecn/ecn0003.txt: Replace balun and filter with integrated balun
(pending)
- TODO: one more CNTR-related task
Files: TODO (1 diff)
atrf/atrf.sch (4 diffs)
atrf/ecn/INDEX (1 diff)
atrf/ecn/ecn0001.txt (1 diff)
atrf/ecn/ecn0002.txt (1 diff)
atrf/ecn/ecn0003.txt (1 diff)
atrf/wpan-atrf.brd (12 diffs)

Change Details

TODO
132132  old.max < curr.min or old.min > curr.max, we have a problem) and to further
133133  narrow the effective margin, thus achieving faster convergence. We would have
134134  to consider temperature drift of the frequency source in this case.
135
136- find out why frequency measurements always seem to start high and then slowly
137  drop
atrf/atrf.sch
1EESchema Schematic File Version 2 date Wed Aug 25 19:40:58 2010
1EESchema Schematic File Version 2 date Thu Aug 26 00:07:13 2010
22LIBS:power
33LIBS:device
44LIBS:conn
...... 
77LIBS:mini_usb_b
88LIBS:xtal-4
99LIBS:antenna
10LIBS:wpan-atrf-cache
1011EELAYER 24 0
1112EELAYER END
1213$Descr A4 11700 8267
1314Sheet 3 3
1415Title "IEEE 802.15.4 USB Transceiver (AT86RF230)"
15Date "20 aug 2010"
16Date "26 aug 2010"
1617Rev "100820"
1718Comp "Werner Almesberger"
1819Comment1 ""
...... 
619620U 1 1 4C640A7B
620621P 10100 2450
621622F 0 "C15" H 10150 2550 50 0000 L CNN
622F 1 "NC" H 10150 2350 50 0000 L CNN
623F 1 "12pF" H 10150 2350 50 0000 L CNN
623624F 2 "0402" H 10100 2450 60 0001 C CNN
624625    1 10100 2450
625626    0 -1 1 0
...... 
639640U 1 1 4C640A73
640641P 10100 1150
641642F 0 "C14" H 10150 1250 50 0000 L CNN
642F 1 "NC" H 10150 1050 50 0000 L CNN
643F 1 "12pF" H 10150 1050 50 0000 L CNN
643644F 2 "0402" H 10100 1150 60 0001 C CNN
644645    1 10100 1150
645646    0 -1 1 0
atrf/ecn/INDEX
1Number Status Description
2------ ------- ---------------------------------------------------------------
30001 Edit Adjust balun component values
40002 Done Add load capacitors to 16 MHz crystal
50003 Edit Replace balun and filter with integrated balun
atrf/ecn/ecn0001.txt
1Adjust balun component values
2
3Some of the components specified in the schematics were not at hand
4in my lab and were thus replaced with similar parts. Furthermore, the
5LED color was changed to ease visual identification:
6
7Component Norminal Board 1 Board 2
8--------------- --------------- --------------- -------------------
9LED (D1) red red red-orange
10C6/C7 0.82 pF 0.7 pF 0.9 pF
11L2/L3 4.3 nH 4.7 nH 4.7 nH
12
13The resulting spectrum should be examined to determine which variant
14performs better. Note that the discrete balun circuit shall be
15replaced with an integrated balun later on.
atrf/ecn/ecn0002.txt
1Add load capacitors to 16 MHz crystal (C14, C15)
2
3The crystal has a specified load capacitance of 8 pF. The AT86RF230 has
4an internal capacitor array that can be trimmed in 16 steps from 0 pF to
54.5 pF.
6
7The crystal has a nominal tolerance of 15 ppm at 25 C plus a temperature
8tolerance of 15 ppm. The following deviations from 1 MHz at CLKM were
9measured with the CNTR board, roughly at 20-25 C:
10
11Board Error Meas. accuracy C14/C15 Trim
12        (f, ppm) (ppm, nom.) (pF) (pF)
13--------------- --------------- --------------- ------------ --------
142, "orange" +268 99.6 NC 0
15        +266 99.5 NC 0
16        +266 40.0 NC 0
17        +148 99.8 NC 3.0
18        +147 99.7 NC 3.0
19        +147 40.0 NC 3.0
20        +111 100.0 NC 4.5
21        +110 99.8 NC 4.5
22        - 13 99.9 15 0
23        - 14 100.0 15 0
24        + 11 99.9 12 0
25        + 11 99.6 12 0
26
271, "red" +263 99.7 NC 0
28        +263 100.0 NC 0
29        +107 99.3 NC 4.5
30        +108 100.0 NC 4.5
31        + 24 99.8 10 0
32        + 24 100.0 10 0
33        - 9 99.7 10 4.5
34        - 9 100.0 10 4.5
35
36(Multiple measurements to assess CNTR performance and drift. Note that
37CNTR measurements are repeatable within 1 ppm, so the nominal accuracy
38appears to be far too pessimistic.)
39
40These measurements suggest that, combined with parasitic capacitance,
41load capacitors of 12 pF make the crystal roughly half the trim range
42faster than 16 MHz.
atrf/ecn/ecn0003.txt
1Replace balun and filter with integrated balun
2
3(pick suitable balun)
atrf/wpan-atrf.brd
1PCBNEW-BOARD Version 1 date Wed Aug 25 19:41:49 2010
1PCBNEW-BOARD Version 1 date Thu Aug 26 00:07:51 2010
22
33# Created by Pcbnew(2010-08-11 BZR 2448)-unstable
44
...... 
2020$SHEETDESCR
2121Sheet A4 11700 8267
2222Title "IEEE 802.15.4 USB Transceiver (AT86RF230)"
23Date "25 aug 2010"
23Date "26 aug 2010"
2424Rev "100820"
2525Comp "Werner Almesberger"
2626Comment1 ""
...... 
341341Op 0 0 0
342342At SMD
343343T0 0 -150 200 200 1800 40 N V 25 N"C15"
344T1 0 150 200 200 1800 40 N I 25 N"NC"
344T1 0 150 200 200 1800 40 N I 25 N"12pF"
345345DS -305 168 -305 -168 50 21
346346DS -305 -168 305 -168 50 21
347347DS 305 -168 305 168 50 21
...... 
369369Op 0 0 0
370370At SMD
371371T0 0 -150 200 200 0 40 N V 25 N"C14"
372T1 0 150 200 200 0 40 N I 25 N"NC"
372T1 0 150 200 200 0 40 N I 25 N"12pF"
373373DS -305 168 -305 -168 50 21
374374DS -305 -168 305 -168 50 21
375375DS 305 -168 305 168 50 21
...... 
27602760ZAux 4 E
27612761ZClearance 80 T
27622762ZMinThickness 70
2763ZOptions 1 16 S 100 80
2763ZOptions 1 16 F 100 80
27642764ZCorner 48800 40500 0
27652765ZCorner 48800 34300 0
27662766ZCorner 40700 34300 0
...... 
31323132ZAux 6 E
31333133ZClearance 80 T
31343134ZMinThickness 70
3135ZOptions 1 16 S 100 80
3135ZOptions 1 16 F 100 80
31363136ZCorner 62100 41100 0
31373137ZCorner 62100 39100 0
31383138ZCorner 56100 39100 0
...... 
32723272ZAux 4 E
32733273ZClearance 80 T
32743274ZMinThickness 70
3275ZOptions 1 16 S 100 80
3275ZOptions 1 16 F 100 80
32763276ZCorner 53900 41100 0
32773277ZCorner 53900 38400 0
32783278ZCorner 52600 38400 0
...... 
33573357ZAux 7 E
33583358ZClearance 80 T
33593359ZMinThickness 70
3360ZOptions 1 16 S 100 80
3360ZOptions 1 16 F 100 80
33613361ZCorner 52500 41100 0
33623362ZCorner 52500 38400 0
33633363ZCorner 52000 38400 0
...... 
36313631ZAux 4 E
36323632ZClearance 80 T
36333633ZMinThickness 70
3634ZOptions 1 16 S 100 80
3634ZOptions 1 16 F 100 80
36353635ZCorner 53900 41100 0
36363636ZCorner 53900 38400 0
36373637ZCorner 52600 38400 0
...... 
38243824ZAux 7 E
38253825ZClearance 80 T
38263826ZMinThickness 70
3827ZOptions 1 16 S 100 80
3827ZOptions 1 16 F 100 80
38283828ZCorner 52500 41100 0
38293829ZCorner 52500 38400 0
38303830ZCorner 52000 38400 0
...... 
38973897ZAux 4 E
38983898ZClearance 80 T
38993899ZMinThickness 70
3900ZOptions 1 16 S 100 80
3900ZOptions 1 16 F 100 80
39013901ZCorner 56100 41100 0
39023902ZCorner 56100 36800 0
39033903ZCorner 54200 36800 0
...... 
42044204ZAux 11 E
42054205ZClearance 80 T
42064206ZMinThickness 70
4207ZOptions 1 16 S 100 80
4207ZOptions 1 16 F 100 80
42084208ZCorner 50600 39100 0
42094209ZCorner 50800 38900 0
42104210ZCorner 51200 38900 0

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