W6810ES Datasheet, PDF (3/6 Pages) Winbond – Single Channel CODEC Mini Evaluation Board

3.2 Schematics
R10
R1
1.5K
J23
MIC+
1
SPK-
2
3
SPK+
4
MIC-
CON4
VCC
J21
1
R2
1.5K
CON1
J22
1
CON1
C2
0.1uF
C3
0.1uF
1K
+ C4
4.7uF @10v
R3 1K
C7 1200pf
R5 27K
R9
27K
R4 1K
R8
3K
C8 1200pf
R6
27K
R7 20K
C6
0.1uF
0 Ohm
R11
VCC
VCC
U1
AO 17
18
19
VAG 20
VREF 1
RO- 2
PAI 3
PAO- 4
PAO+ 5
AO
AI-
AI+
VAG
VREF
RO-
PAI
PAO-
PAO+
C5
0.1uF
C1
0.1uF
14
FST
BCLKT
PCMT
12
13
MCLK ¹¹
PCMR
BCLKR
8
9
7
FSR
FST
BCLKT
PCMT
MCLK
PCMR
BCLKR
FSR
u/A
16
10
U/A
PUI
PUI
W68XXXX
R12
2K
(FRAME SYNC TRANSMIT)
(BIT CLOCK TRANSMIT)
(PCM OUTPUT)
(2.048 MHz MASTER CLOCK IN)
(PCM INPUT)
(BIT CLOCK RECEIVE)
(FRAME SYNC RECEIVE)
(PCM MODE CONTROL)
(POWER CONTROL)
W6810, W681512 or W681310
are Populated with C6 and R11 as shown
below.
C6
R11
Device Number
Populated
Not Populated
W6810
Not Populated Not Populated
W681512
Populated
Not Populated
W681310
VREF
RO-
PAI
PAO-
PAO+
VCC
J1
1
CON1
J2
1
CON1
J3
1
CON1
J4
1
CON1
J5
1
CON1
J6
1
CON1
FSR
PCMR
BCLKR
PUI
MCLK
BCLKT
J7
1
CON1
J8
1
CON1
J9
1
CON1
J10
1
CON1
J11
1
CON1
J12
1
CON1
PCMT
FST
J13
1
CON1
J14
1
CON1
J15
1
CON1
U/A
AO
AI-
J16
1
CON1
J17
1
CON1
J18
1
CON1
AI+
VAG
J19
1
CON1
J20
1
CON1
Figure 1: EW681xxxES Board Schematics Telephone Handset Default Diagram
4 Connecting Microphone and Speaker to the W681xxxES
J23 can be used to connect an RJ9 plug from a “standard” telephone handset or headset to the
appropriate pins on the board (Table 4.0). The default resistor and capacitor values on the board are used
for the maximum amplification with no saturation of a 32ohm speaker using a standard microphone.
Unfortunately the only thing “standard” about the RJ9 handset jack is that the microphone and speaker are
always on the same pins. BUT, the microphone polarity can be positive, or negative, depending upon how
the manufacturer designed their telephone set. This means that one has about a 50% chance of wiring it
up wrong the first time UNLESS you know ahead of time which polarity handset you have. Many years
ago, with carbon microphones acting as variable resistors this was not an issue. But with today’s modern
handsets using polarized electret microphones polarity is very important. The circuit in Figure 1 assumes
that the positive side of the microphone is connected to pin 1 of the RJ9 plug and the negative side to pin 4.
Reversing the wires from the RJ9 to the holes in J23 will solve the polarity problem if there is no audio.
Pin1 Pin2 Pin3
Pin4
Mic+ Speaker- Speaker+ Mic -
Table 4.0 : J23 Pin assignments
3