LG F1200 Service Manual page 26

B. Speaker Amplifier (TPA2005)
TPA2005 is a mono power amplifier for loud speaker. Two amplifiers are used for stereo
operation. It drives a speaker up to 1W power in full differential mode. In F1200, input signals
are single-ended mode and output signals are differential mode. Speaker Amplifier is
controlled with SPK_EN signal from DBB (Calypso plus) which can enable or disable the
amplifiers.
R518
1K
R532
1K
C. Headphone Amplifier (LM4809LD)
LM4809LD is a stereo headphone amplifier. It includes two amplifiers, which can drive a ear-
piece up to 70mW power. The LM4809LD operates in single-ended mode and controlled with
HP_AMP_EN signal from DBB (Calypso plus).
HP_AMP_EN
C511 U501 TPA2005D1GQYR
R516
D1
IN-
15K
0.1u
R517
C1
IN+
15K
A1
C512 C533 _SD
8200p 0.1u
SPK_EN
U503 TPA2005D1GQYR
C532
R529
D1
IN-
0.1u 15K
R530
C1
IN+
15K
A1
C536 C535 _SD
8200p 0.1u
Figure 13. Speaker Amplifier circuits
C534
1u
C540 1u R533 15K
C537 1u R531 15K
C538
220n
Figure 14. Headphone Amplifier circuits
- 25 -
3. TECHNICAL BRIEF
C525 C519
B4
VDD1 1u 10u
C4
VDD2
B1
NC
A4
VO- SPKL_N
D4
VO+ SPKL_P
C510 C524
47p 47p
C521 C520
B4
VDD1 1u 10u
C4
VDD2
B1
NC
A4
VO- SPKR_N
D4
VO+ SPKR_P
C522 C523
47p 47p
R528
62K
R527
62K
U504 LM4809LD
7 8
VDD VOUT1
1
VIN1
6
VOUT2
5
VIN2
2 3
BYPASS GND
4 9
_SHDN BGND