Dual Mode Speaker And Midi Ic - LG C3100 Service Manual

3. TECHNICAL BRIEF

3.12 Dual Mode Speaker and MIDI IC

(1) Dual Mode Speaker
There is a control signal (SPK_RCV_EN) which is for enabling receiver or speaker because one
dual mode speaker is used for both receiver and speaker. The signal is produced by AD6525
and controls the analog switch (U201).
The dual mode speaker is placed in the front cover and contacted to PCB.
A. Receiver Operation
The dual mode speaker is driven by VOUTNORP and VOUTNORN of AD6521 through a
analog switch (U201) when it is used for receiver. The gain is controlled by the PGA in
AD6521.
B. Speaker Operation
The dual mode speaker is driven by SPOUT1 and SPOUT2 of YMU759B (U200) through the
analog switch (U201) when it is used for loud speaker.
R234
0
R236
0
R206
RCVP
R207
RCVN
SPK_RCV_EN
C200
39p
U201
NLAS4684MR2
1 10
V+ NO2
2 9
NO1 COM2
3 8
COM1 IN2
4 7
IN1 NC2
5 6
NC1 GND
4.7
C207
39p
4.7
C210
39p
Figure 3-18. Circuit Diagram of Dual Mode Speaker.
C208
47p
- 32 -
C211 C212
39p 39p
CN200
1
2