Waveforms On System Test; Power On System Reset Sequence; System 27 Mhz Clock Waveform - LG BP340 Service Manual

WAVEFORMS ON SYSTEM TEST

1. POWER ON SYSTEM RESET SEQUENCE

RESET active high must delay basis on all system power.
RESET_
1
1.2V
2
Figure 1-1. Waveform

2. SYSTEM 27 MHz CLOCK WAVEFORM

MT8551 require nominal frequency 27 MHz, tolerance ±30 ppm.
3
27MHz
Figure 2-1. Waveform
VCC
R181 R181 R176 R176
12K 12K 3.3K 3.3K
R177 R177 100 100
R182 R182 Q1 Q1
2.7K 2.7K NPN_3DG3904M NPN_3DG3904M
Figure 1-2. Test Point
3.3V_STBY
C86 C86 33pF/50V/NP0 33pF/50V/NP0
Y1 Y1
27MHz/30PPM 27MHz/30PPM
C87 C87 33pF/50V/NP0 33pF/50V/NP0
3
Figure 2-2. Test Point
3-10
3.3V_STBY
1
R179 R179
10K 10K
RESET_ RESET_
Q4 Q4
C214 C214
NPN_3DG3904M NPN_3DG3904M
4.7UF/10V/X 5R 4.7UF/10V/X 5R
RESET
2
1.2V
U1C U1C
AVDD33_VDAC E16
3.3V
AVDD33_VDAC
G14
AVSS33_VDAC
AVDD33_VDAC_R D16
3.3V
AVDD33_VDAC_R
F14
AVSS33_VDAC_R
AVDD33_PLLGP C12
AVDD33_PLLGP
C13
AVSS33_PLLGP
NS_XTALI A11
NS_XTALI
R41 R41
1M 1M
R43 R43 10 10 NS_XTALO B11
NS_XTALO
RESET_
A
A