r5214 - in trunk/gta02-core: . docs/ecn
rehar at docs.openmoko.org
rehar at docs.openmoko.org
Fri Jun 26 00:00:30 CEST 2009
Author: rehar
Date: 2009-06-26 00:00:29 +0200 (Fri, 26 Jun 2009)
New Revision: 5214
Modified:
trunk/gta02-core/audio.sch
trunk/gta02-core/docs/ecn/STATUS
trunk/gta02-core/docs/ecn/ecn0010.txt
trunk/gta02-core/docs/ecn/ecn0022.txt
Log:
updated ECN0022 and ECN0010, chaged status to discuss
moved R4116/R4117 behind R4407/R4405
Modified: trunk/gta02-core/audio.sch
===================================================================
--- trunk/gta02-core/audio.sch 2009-06-25 17:50:58 UTC (rev 5213)
+++ trunk/gta02-core/audio.sch 2009-06-25 22:00:29 UTC (rev 5214)
@@ -1,4 +1,4 @@
-EESchema Schematic File Version 2 date Do 25 Jun 2009 12:50:34 CDT
+EESchema Schematic File Version 2 date Do 25 Jun 2009 16:47:50 CDT
LIBS:power,device,conn,gta02-core
EELAYER 24 0
EELAYER END
@@ -13,6 +13,17 @@
Comment3 ""
Comment4 ""
$EndDescr
+Connection ~ 13150 9000
+Wire Wire Line
+ 13150 9300 13150 9000
+Connection ~ 12650 8600
+Wire Wire Line
+ 13350 8600 12150 8600
+Connection ~ 14050 8600
+Wire Wire Line
+ 14050 9300 14050 8600
+Wire Wire Line
+ 13850 9000 14900 9000
Connection ~ 9350 3950
Wire Wire Line
9350 3950 9350 3650
@@ -116,12 +127,9 @@
3100 10550 3100 10350
Wire Wire Line
2900 9250 2900 9650
-Connection ~ 14450 9000
Wire Wire Line
- 14450 9000 14450 9300
+ 14050 10050 14050 9800
Wire Wire Line
- 13950 10050 13950 9800
-Wire Wire Line
10200 8150 14250 8150
Connection ~ 14250 8150
Wire Wire Line
@@ -129,18 +137,13 @@
Wire Wire Line
14250 8700 14900 8700
Wire Wire Line
- 12150 9000 12600 9000
-Connection ~ 13500 8600
-Wire Wire Line
- 13500 9300 13500 8600
-Wire Wire Line
10200 4950 9700 4950
Wire Wire Line
9700 4950 9700 3950
Wire Wire Line
9700 3950 8850 3950
Wire Wire Line
- 14450 10050 14450 9800
+ 13150 10050 13150 9800
Wire Wire Line
14700 9300 14700 9100
Wire Wire Line
@@ -455,10 +458,8 @@
Wire Wire Line
9800 3850 9800 4800
Wire Wire Line
- 13500 9800 13500 10050
+ 12650 9800 12650 10050
Wire Wire Line
- 12150 8600 12600 8600
-Wire Wire Line
14650 8900 14900 8900
Wire Wire Line
14250 7200 14250 7450
@@ -467,13 +468,6 @@
Wire Wire Line
8900 8150 9100 8150
Wire Wire Line
- 14900 9000 13100 9000
-Wire Wire Line
- 13100 8600 14900 8600
-Wire Wire Line
- 13950 9300 13950 8600
-Connection ~ 13950 8600
-Wire Wire Line
2900 9150 2900 8750
Wire Wire Line
3300 8950 3300 8750
@@ -605,6 +599,12 @@
12150 3200 12350 3200
Wire Wire Line
12150 3150 11950 3150
+Wire Wire Line
+ 13850 8600 14900 8600
+Wire Wire Line
+ 12650 8600 12650 9300
+Wire Wire Line
+ 12150 9000 13350 9000
$Comp
L EXC24CB102U B4102
U 1 1 4A43AD85
@@ -997,20 +997,20 @@
$Comp
L GND #PWR?
U 1 1 4A413D33
-P 13950 10050
-F 0 "#PWR?" H 13950 10050 30 0001 C CNN
-F 1 "GND" H 13950 9980 30 0001 C CNN
- 1 13950 10050
+P 14050 10050
+F 0 "#PWR?" H 14050 10050 30 0001 C CNN
+F 1 "GND" H 14050 9980 30 0001 C CNN
+ 1 14050 10050
1 0 0 -1
$EndComp
$Comp
L VARISTOR D4402
U 1 1 4A413D29
-P 13950 9550
-F 0 "D4402" H 13950 9700 60 0000 C CNN
-F 1 "5.6Vac, 150pF" H 13950 9400 60 0000 C CNN
-F 2 "0402" H 13890 9760 60 0001 C CNN
- 1 13950 9550
+P 14050 9550
+F 0 "D4402" H 14050 9700 60 0000 C CNN
+F 1 "5.6Vac, 150pF" H 14050 9400 60 0000 C CNN
+F 2 "0402" H 13990 9760 60 0001 C CNN
+ 1 14050 9550
0 1 1 0
$EndComp
Text GLabel 13250 7750 2 60 Output ~ 0
@@ -1109,40 +1109,40 @@
$Comp
L R_US R4405
U 1 1 4A41220C
-P 12850 9000
-F 0 "R4405" H 12850 9100 50 0000 C CNN
-F 1 "0R" H 12850 8900 50 0000 C CNN
-F 2 "0402" H 12800 9150 60 0001 C CNN
- 1 12850 9000
+P 13600 9000
+F 0 "R4405" H 13600 9100 50 0000 C CNN
+F 1 "0R" H 13600 8900 50 0000 C CNN
+F 2 "0402" H 13550 9150 60 0001 C CNN
+ 1 13600 9000
1 0 0 -1
$EndComp
$Comp
L R_US R4407
U 1 1 4A412206
-P 12850 8600
-F 0 "R4407" H 12850 8700 50 0000 C CNN
-F 1 "0R" H 12850 8500 50 0000 C CNN
-F 2 "0402" H 12800 8750 60 0001 C CNN
- 1 12850 8600
+P 13600 8600
+F 0 "R4407" H 13600 8700 50 0000 C CNN
+F 1 "0R" H 13600 8500 50 0000 C CNN
+F 2 "0402" H 13550 8750 60 0001 C CNN
+ 1 13600 8600
1 0 0 -1
$EndComp
$Comp
L GND #PWR?
U 1 1 4A3F175F
-P 13500 10050
-F 0 "#PWR?" H 13500 10050 30 0001 C CNN
-F 1 "GND" H 13500 9980 30 0001 C CNN
- 1 13500 10050
+P 12650 10050
+F 0 "#PWR?" H 12650 10050 30 0001 C CNN
+F 1 "GND" H 12650 9980 30 0001 C CNN
+ 1 12650 10050
1 0 0 -1
$EndComp
$Comp
L R_US R4117
U 1 1 4A3F1756
-P 13500 9550
-F 0 "R4117" H 13500 9650 50 0000 C CNN
-F 1 "1k" H 13500 9450 50 0000 C CNN
-F 2 "0402" H 13450 9700 60 0001 C CNN
- 1 13500 9550
+P 12650 9550
+F 0 "R4117" H 12650 9650 50 0000 C CNN
+F 1 "1k" H 12650 9450 50 0000 C CNN
+F 2 "0402" H 12600 9700 60 0001 C CNN
+ 1 12650 9550
0 -1 1 0
$EndComp
Text GLabel 9600 5200 2 60 Output ~ 0
@@ -1161,20 +1161,20 @@
$Comp
L GND #PWR?
U 1 1 4A3F13DD
-P 14450 10050
-F 0 "#PWR?" H 14450 10050 30 0001 C CNN
-F 1 "GND" H 14450 9980 30 0001 C CNN
- 1 14450 10050
+P 13150 10050
+F 0 "#PWR?" H 13150 10050 30 0001 C CNN
+F 1 "GND" H 13150 9980 30 0001 C CNN
+ 1 13150 10050
1 0 0 -1
$EndComp
$Comp
L R_US R4116
U 1 1 4A3F13C7
-P 14450 9550
-F 0 "R4116" H 14450 9650 50 0000 C CNN
-F 1 "1k" H 14450 9450 50 0000 C CNN
-F 2 "0402" H 14400 9700 60 0001 C CNN
- 1 14450 9550
+P 13150 9550
+F 0 "R4116" H 13150 9650 50 0000 C CNN
+F 1 "1k" H 13150 9450 50 0000 C CNN
+F 2 "0402" H 13100 9700 60 0001 C CNN
+ 1 13150 9550
0 -1 1 0
$EndComp
Text GLabel 9850 8650 0 60 Input ~ 0
@@ -1215,8 +1215,6 @@
1 15300 8850
1 0 0 -1
$EndComp
-Text Notes 11650 9250 0 60 ~ 0
-f_cuttoff=50Hz \n@ C=100uF and\nZ_headphone=32 OHM?\nform factor @6.3V 1206\n\nMaybe better to switch to DC mode \nphysical cap size will get quit big. \n(problem: GND for MICRO????)
$Comp
L C C4110
U 1 1 4A3EFB33
Modified: trunk/gta02-core/docs/ecn/STATUS
===================================================================
--- trunk/gta02-core/docs/ecn/STATUS 2009-06-25 17:50:58 UTC (rev 5213)
+++ trunk/gta02-core/docs/ecn/STATUS 2009-06-25 22:00:29 UTC (rev 5214)
@@ -9,7 +9,7 @@
0007 Discuss Remove KEEPACT net and connect PMU.KEEPACT directly to IO_3V3
0008 Edit Remove external GPS antenna connector and circuit (CON7602)
0009 Discuss Remove LED transistors (Q1501 and Q1502)
-0010 Edit Remove audio amplifier (U4101)
+0010 Discuss Remove audio amplifier (U4101)
0011 Edit Reduce number of varistors on USB_VBUS (C4902, C4909)
0012 Defer Add fuse to USB_VBUS
0013 Defer Increase rated current of B4902
@@ -21,5 +21,5 @@
0019 Edit Consider applying buzz fix
0020 Discuss No common mode choke on stereo signals (B4102)
0021 Defer Use EMI-hardened microphone (MC4301)
-0022 Edit Apply bass fix
+0022 Discuss Apply bass fix
0023 Edit Fix #1024 (C1009)
Modified: trunk/gta02-core/docs/ecn/ecn0010.txt
===================================================================
--- trunk/gta02-core/docs/ecn/ecn0010.txt 2009-06-25 17:50:58 UTC (rev 5213)
+++ trunk/gta02-core/docs/ecn/ecn0010.txt 2009-06-25 22:00:29 UTC (rev 5214)
@@ -7,24 +7,22 @@
Removing the external amplifier (U4101) as well as the amplifier specific
components R4114, R4112, R4109, R4108, R4110, R4113, C4117, C4111, C4110, C4110
-and C4115. Also there is no need for the AMP_SHUTDOWN and HP_IN signals anymore, the external
-speaker and headphone can be fully controlled by the corresponding register settings of the
-codec. (see [1])
+and C4115. Also there is no need for the AMP_SHUTDOWN and HP_IN signals anymore,
+the external speaker and headphone can be fully controlled by the corresponding
+register settings of the codec. (see [1])
-The GTA02 earpiece will be connected between OUT3 and ROUT1 of the codec, there will be
-no change on the filter and bypass capacitors.
+The GTA02 earpiece will be connected between OUT3 and LOUT1 of the codec, there
+will be no change of the filter and bypass capacitors.
The external speaker will be connected directly between ROUT2 and LOUT2.
-Filter and capacitors will be the same.
+Filter, capacitors, and varistors will not be changed or replaced.
+The external headphone will be connected between ROUT1 and LOUT2, the common
+mode choke B4102 will be inserted in the stereo path of the headphone.
[1] http://www.wolfsonmicro.com/uploads/documents/en/WM8753.pdf
-TODO:
-- Headphone switch to GPIO4
-- massive change of components (C4405,R4405 etc) headphone jack,
- improve audio quality for low impedance headsets at low frequencies
-- reason for varistor on EP_L line
-- maybe increase the pull down resistors (R4117 and R4116) for high
- impedance headphones (Z >= 2k OHM).
\ No newline at end of file
+
+Author: Rene Harder <rehar at saweb.de>
+
Modified: trunk/gta02-core/docs/ecn/ecn0022.txt
===================================================================
--- trunk/gta02-core/docs/ecn/ecn0022.txt 2009-06-25 17:50:58 UTC (rev 5213)
+++ trunk/gta02-core/docs/ecn/ecn0022.txt 2009-06-25 22:00:29 UTC (rev 5214)
@@ -1,6 +1,25 @@
Apply bass fix
-To do:
-- more details - what is actually involved ?
-- is this part of the switch to a "capless" design ?
+The GTA02 has a 1uF cap in the left and right audio path of the
+headphone, these caps act in combination with the headphone as high-pass
+filter, so they will attenuate the lower frequencies. For a headphone with
+32 Ohm impedance the resulting cutoff frequency will be 2.45kHz (incl. 33 Ohm
+internal R). This result in a poor audio quality if listening to music.
+
+Unfortunately we cannot switch to the dc coupled (capless) design because we
+share a common ground with the microphone. In capless mode we would be unable
+to bias the microphone properly. To solve this issue we would need a headset
+with a separate ground for microphone and headphone as well as a different
+headset jack.
+
+To improve the audio quality we need to replace C4111 and C4110 with a 100uF
+capacitor so the lower cutoff frequency with a 32 Ohm headphone will be at 50Hz
+(assumes R4407 & R4405 = 0R, see "Removal of Calypso serial interface on the
+headset jack")
+
+
+Author: Rene Harder <rehar at saweb.de>
+
+
+
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