rpi-dac singlestereo dac rev. 6 - tjaekel · 2014. 7. 2. · rpi-dac singlestereo dac rev. 6 solder...
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![Page 1: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/1.jpg)
RPi-DAC SingleStereo DAC rev. 6solder with 1m and 47m (on In and Out) , check voltages before soldering other parts
solder all other parts, excluding the active components such as OpAmp, PCM1794A ad TPA6120A
measure again all voltages: 2x +15C, 2x -15V, 1x6V, 1x3.3V
if all OK, solder OpAmp, PCM1794A and TPA6120A
power always all rails, esp. the + and -15V,
all LDOs first
never power just one rail
Solder Options:
if fed with DC: the BRECT and electrolyte caps are not needed: use 0R instead of BRECT
not all 47m (or 1m) Cb are needed, some can be omitted
For I/V converter (4x OpAmp) use OPA827 or LME49990
the LEDs (as indicators for the power rails) plus R can be optional
the jumper headers and jumpers can be fix soldered as 0R
the OSC (XTAL) is not used or needed, just if external FPGA or other components
some Cb (1206) as 47m/25V can be also changed to 68m/10V (depends on which rail used)
all Cb (0603) without value mentioned can be 0.1m or 1m (ATT: one 1m used on LDOs)
Improvements:
Use metal film resistors if located in signal path (825R, 1K, 1.5K, 10R)
Use NPO/CG0 caps (5.6n) if in signal path
Use OPA827 instead of LME49990 for I/V converter (JFET, but higher noise and THD)
Attention:
Use AC or DC in for the +15 and -15V railwithout any common center tap (with separated coils),no common connection between both!
![Page 2: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/2.jpg)
RPi-DAC SingleStereo Top
OpAmp OpAmp
OpAmpOpAmp
TPA6120A
PC
M1794A
+
+
+
+
C (0603)
R (0603)
Cb (1206)47m/25V
male header + jumper
LED (0603)
male connector
female connector
OSC
33R
33R
33R
33R
10K
10K
10K
10K
10K
10K
10K
8.2K
825R 825R
5.6n 5.6n
825R 825R
5.6n 5.6n130R
1.3K
1.3K
1.3K
10R
10R
1K1K
1K 1K
1.5K
1.5K
1.5K
1.5K
1.3K
+
+
+
+
BRECT
BRECT
BR
EC
T
BR
EC
Toptional
Cb (0603) 0.1..1m
+
1m
1m 1m
1m
1m
1m
+ -GND
GND + -
LDO
LDO
LDO
LDOLDO
LDO
GND
GNDn.c.
n.c.
HeadphoneRCA Out
I2S In
OpAmp: OPA827 or LME49990
3.3V
6V
+15V
-15V
-15V
+15V
solder LDO first and measure voltage
47m47m
LDO : TPS7A4700
6V
6V
6V
GND
6V
AC6..9V
AC15V
AC15V
BCK
LRCK
DATA
5V
3.3V
n.c.
sep
ara
ted
co
ils!
ACs in for the +15 and -15V rails have to comefrom separated coils, no center tap, no commonGND or connection!
![Page 3: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/3.jpg)
RPi-DAC SingleStereo Bottom solder power pad before electrolyte
electrolyte just if AC input, with DC not neededoptional
+ +
+
+
+ +
+
+
+
6V
3.3V
+ grounded
+ grounded
![Page 4: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/4.jpg)
![Page 5: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/5.jpg)
RPi-DAC SingleStereo Top
![Page 6: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/6.jpg)
RPi-DAC SingleStereo Bottom
![Page 7: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/7.jpg)
PCM1794A 15P
15N
+3.3V
+6V
+15V
-15V
I2S
OUTR
+7V
+16V
1A
+DVDD
+AVDD
AGND
AGND
DGND
DGND
AGND
R+
R-
AGND
AGND
15P
15N
OUTL
AGND
L+
L-
AGND
TPS7A4700
+15V
-15V
6x TPS7A4700
+16V
AGND
OUTR
OUTL
4x LME49990 TPA6120A
RPi-DAC
24bit, 192KHz
0.0004% THD+N120dB Channel Sep.?? PSRR?? Noise
127dB SNR
127dB CMRR0.00001% THD+N-144dB PSRR1.3nV/sqrt(Hz)
-79dB PSRR
120dB SNR0.0006% THD+N
5mVrms Noise
+16VTPS7A4700
TPS7A4700
TPS7A4700
TPS7A4700
TPS7A47001A
1A
1A
1A
1A
FMT
-82dB PSRR (100Hz)4.17mVrms Noise
Headphone:Sennheiser HD800
300Ohm0.02% THD
+6V
I/V Converter
+
+
-16V
+16V
-16V
+6V
+3.3V
![Page 8: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/8.jpg)
MONO
CHSL
DEM
LRCK
DATA
BCK
SCK
DGND
VDD
MUTE
FMT0
FMT1
ZERO
/RST
VCC2L
AGND3L
IOUTL-
IOUTL+
AGND2
VCC1
VCOML
VCOMR
IREF
AGND1
IOUTR-
IOUTR+
AGND3R
VCC2R
1
2
3
4
5
6
7
8
9
10
11
12
13
14 15
16
17
18
19
20
21
22
23
24
25
26
27
28PCM1794A
3.3V
3.3V
3.3V
6V
6V
6V
AGND
AGND
AGND
AGND
AGND
DGND
DGND
DGND
DGND
AGND
AGND
15P
15N
-
+
15P
15N
-
+
15P
15N
-
+
15P
15N
-
+
LVCC-
LOUT
LVCC+
LIN+
LIN-
n.c.
RVCC-
ROUT
RVCC+
RIN+
RIN-
1
2
3
4
5
6
7
8
9
10 11
12
13
14
15
16
17
18
19
20TPA6120A
n.c.
n.c.
n.c.
n.c.
n.c.
n.c.
n.c.
n.c.
n.c.
POWERPAD
OUTR+
OUTR-
OUTR
15P
15N
gain: 2.5V/V
LRCK
DATA
BCK
SCK
IOUTL-
IOUTL+
IOUTL+
IOUTL-
10K
10K 10K
10K
33R
33R
33R
33R
10K
47m
47m
10K
10..30R
825R
10K
4x LME49990
15N
OUTL-
OUTL+
OUTR+
OUTR-15P
OUTL
OUTL+
OUTL-
47m
47m
47m
47m
100n
100n
100n
100n
47m
47m
100n
100n
100n
100n
47m
47m
100n
100n
100n
100n
100n
100n
2
3
6
7
4
2
3
6
7
4
4
72
3
6
6
7
4
2
3
100n
100n
AGND
AGND
AGND
AGND
RPi-DAC SingleStereo
Ipp = 7.8mA
f =34.5KHz
Vpp = * -7.8mAVrms = Vpp / sqrt(2)
825R
keep Vrms ~ 8V (<9V)
keep Vpp ~ 17V
keep Vpp < 3.5...4V
keep gain: 2..3V/V
I2S
J1
J2
10K
1K
5.6n
1K
1.5K
1.5K
1.5K
1K
1K
1.5K
10..30R
825R
825R
825R
5.6n
5.6n
5.6n
8.2K
or: 4x OPA827
CG0/NPOmetal film
![Page 9: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/9.jpg)
1
56 10
11
151620
C147m
IN
C247m
OUT
SENSE
C31m
NR
6.4V2
6.4V1
3.2
V
1.6
V
0.8
V
0.4
V
0.2V
0.1V
EN
nc
nc nc nc
TPS7A4700 (pos.)
VOUT = + /Vpin1.4V
+15V
1
56 10
11
151620
C147m
IN
C247m
OUT
SENSE
C31m
NR
6.4V2
6.4V1
3.2
V
1.6
V
0.8
V
0.4
V
0.2V
0.1V
EN
nc
nc nc nc
TPS7A4700 (pos.)
VOUT = + /Vpin1.4V
6VPSRR: Vnoise:
78dB4.67 mVrms
AC
3x separate coils!
DC
47m47m820m820m
1m 1m
2A
DC DC
6x TPS7A4700 (pos.)
4x Bridge Rectifier
1A 1A
PSU (low noise LDOs)
4x
1
56 10
11
151620
C147m
IN
C247m
OUT
SENSE
C31m
NR
6.4V2
6.4V1
3.2
V
1.6
V
0.8
V
0.4
V
0.2V
0.1V
EN
nc
nc nc nc
TPS7A4700 (pos.)
VOUT = + /Vpin1.4V
3.3VPSRR: Vnoise:
78dB4.67 mVrms
1m
DC
1A
on -15V rail - the GND is used, +15V is grounded!
-15V
![Page 10: RPi-DAC SingleStereo DAC rev. 6 - tjaekel · 2014. 7. 2. · RPi-DAC SingleStereo DAC rev. 6 solder with 1m and 47m (on In and Out) , check voltages before soldering other parts solder](https://reader036.vdocument.in/reader036/viewer/2022062415/60aae9833d03cb7e180eb2ed/html5/thumbnails/10.jpg)
RPi-DAC SingleStereo Pictures