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mirror of git://projects.qi-hardware.com/ben-wpan.git synced 2024-11-22 07:51:55 +02:00

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
This commit is contained in:
Werner Almesberger 2010-08-26 00:30:41 -03:00
parent c1b7b81936
commit 5b73e8bb75
7 changed files with 85 additions and 16 deletions

3
TODO
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@ -132,3 +132,6 @@ Things not done yet
old.max < curr.min or old.min > curr.max, we have a problem) and to further
narrow the effective margin, thus achieving faster convergence. We would have
to consider temperature drift of the frequency source in this case.
- find out why frequency measurements always seem to start high and then slowly
drop

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@ -1,4 +1,4 @@
EESchema Schematic File Version 2 date Wed Aug 25 19:40:58 2010
EESchema Schematic File Version 2 date Thu Aug 26 00:07:13 2010
LIBS:power
LIBS:device
LIBS:conn
@ -7,12 +7,13 @@ LIBS:c8051f326
LIBS:mini_usb_b
LIBS:xtal-4
LIBS:antenna
LIBS:wpan-atrf-cache
EELAYER 24 0
EELAYER END
$Descr A4 11700 8267
Sheet 3 3
Title "IEEE 802.15.4 USB Transceiver (AT86RF230)"
Date "20 aug 2010"
Date "26 aug 2010"
Rev "100820"
Comp "Werner Almesberger"
Comment1 ""
@ -619,7 +620,7 @@ L C C15
U 1 1 4C640A7B
P 10100 2450
F 0 "C15" H 10150 2550 50 0000 L CNN
F 1 "NC" H 10150 2350 50 0000 L CNN
F 1 "12pF" H 10150 2350 50 0000 L CNN
F 2 "0402" H 10100 2450 60 0001 C CNN
1 10100 2450
0 -1 1 0
@ -639,7 +640,7 @@ L C C14
U 1 1 4C640A73
P 10100 1150
F 0 "C14" H 10150 1250 50 0000 L CNN
F 1 "NC" H 10150 1050 50 0000 L CNN
F 1 "12pF" H 10150 1050 50 0000 L CNN
F 2 "0402" H 10100 1150 60 0001 C CNN
1 10100 1150
0 -1 1 0

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atrf/ecn/INDEX Normal file
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@ -0,0 +1,5 @@
Number Status Description
------ ------- ---------------------------------------------------------------
0001 Edit Adjust balun component values
0002 Done Add load capacitors to 16 MHz crystal
0003 Edit Replace balun and filter with integrated balun

15
atrf/ecn/ecn0001.txt Normal file
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@ -0,0 +1,15 @@
Adjust balun component values
Some of the components specified in the schematics were not at hand
in my lab and were thus replaced with similar parts. Furthermore, the
LED color was changed to ease visual identification:
Component Norminal Board 1 Board 2
--------------- --------------- --------------- -------------------
LED (D1) red red red-orange
C6/C7 0.82 pF 0.7 pF 0.9 pF
L2/L3 4.3 nH 4.7 nH 4.7 nH
The resulting spectrum should be examined to determine which variant
performs better. Note that the discrete balun circuit shall be
replaced with an integrated balun later on.

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atrf/ecn/ecn0002.txt Normal file
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@ -0,0 +1,42 @@
Add load capacitors to 16 MHz crystal (C14, C15)
The crystal has a specified load capacitance of 8 pF. The AT86RF230 has
an internal capacitor array that can be trimmed in 16 steps from 0 pF to
4.5 pF.
The crystal has a nominal tolerance of 15 ppm at 25 C plus a temperature
tolerance of 15 ppm. The following deviations from 1 MHz at CLKM were
measured with the CNTR board, roughly at 20-25 C:
Board Error Meas. accuracy C14/C15 Trim
(f, ppm) (ppm, nom.) (pF) (pF)
--------------- --------------- --------------- ------------ --------
2, "orange" +268 99.6 NC 0
+266 99.5 NC 0
+266 40.0 NC 0
+148 99.8 NC 3.0
+147 99.7 NC 3.0
+147 40.0 NC 3.0
+111 100.0 NC 4.5
+110 99.8 NC 4.5
- 13 99.9 15 0
- 14 100.0 15 0
+ 11 99.9 12 0
+ 11 99.6 12 0
1, "red" +263 99.7 NC 0
+263 100.0 NC 0
+107 99.3 NC 4.5
+108 100.0 NC 4.5
+ 24 99.8 10 0
+ 24 100.0 10 0
- 9 99.7 10 4.5
- 9 100.0 10 4.5
(Multiple measurements to assess CNTR performance and drift. Note that
CNTR measurements are repeatable within 1 ppm, so the nominal accuracy
appears to be far too pessimistic.)
These measurements suggest that, combined with parasitic capacitance,
load capacitors of 12 pF make the crystal roughly half the trim range
faster than 16 MHz.

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atrf/ecn/ecn0003.txt Normal file
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@ -0,0 +1,3 @@
Replace balun and filter with integrated balun
(pick suitable balun)

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@ -1,4 +1,4 @@
PCBNEW-BOARD Version 1 date Wed Aug 25 19:41:49 2010
PCBNEW-BOARD Version 1 date Thu Aug 26 00:07:51 2010
# Created by Pcbnew(2010-08-11 BZR 2448)-unstable
@ -20,7 +20,7 @@ $EndGENERAL
$SHEETDESCR
Sheet A4 11700 8267
Title "IEEE 802.15.4 USB Transceiver (AT86RF230)"
Date "25 aug 2010"
Date "26 aug 2010"
Rev "100820"
Comp "Werner Almesberger"
Comment1 ""
@ -341,7 +341,7 @@ AR /4C609C08/4C640A7B
Op 0 0 0
At SMD
T0 0 -150 200 200 1800 40 N V 25 N"C15"
T1 0 150 200 200 1800 40 N I 25 N"NC"
T1 0 150 200 200 1800 40 N I 25 N"12pF"
DS -305 168 -305 -168 50 21
DS -305 -168 305 -168 50 21
DS 305 -168 305 168 50 21
@ -369,7 +369,7 @@ AR /4C609C08/4C640A73
Op 0 0 0
At SMD
T0 0 -150 200 200 0 40 N V 25 N"C14"
T1 0 150 200 200 0 40 N I 25 N"NC"
T1 0 150 200 200 0 40 N I 25 N"12pF"
DS -305 168 -305 -168 50 21
DS -305 -168 305 -168 50 21
DS 305 -168 305 168 50 21
@ -2760,7 +2760,7 @@ ZLayer 0
ZAux 4 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 48800 40500 0
ZCorner 48800 34300 0
ZCorner 40700 34300 0
@ -3132,7 +3132,7 @@ ZLayer 0
ZAux 6 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 62100 41100 0
ZCorner 62100 39100 0
ZCorner 56100 39100 0
@ -3272,7 +3272,7 @@ ZLayer 0
ZAux 4 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 53900 41100 0
ZCorner 53900 38400 0
ZCorner 52600 38400 0
@ -3357,7 +3357,7 @@ ZLayer 15
ZAux 7 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 52500 41100 0
ZCorner 52500 38400 0
ZCorner 52000 38400 0
@ -3631,7 +3631,7 @@ ZLayer 15
ZAux 4 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 53900 41100 0
ZCorner 53900 38400 0
ZCorner 52600 38400 0
@ -3824,7 +3824,7 @@ ZLayer 0
ZAux 7 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 52500 41100 0
ZCorner 52500 38400 0
ZCorner 52000 38400 0
@ -3897,7 +3897,7 @@ ZLayer 15
ZAux 4 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 56100 41100 0
ZCorner 56100 36800 0
ZCorner 54200 36800 0
@ -4204,7 +4204,7 @@ ZLayer 0
ZAux 11 E
ZClearance 80 T
ZMinThickness 70
ZOptions 1 16 S 100 80
ZOptions 1 16 F 100 80
ZCorner 50600 39100 0
ZCorner 50800 38900 0
ZCorner 51200 38900 0