ViewSonic N3735w-1M Service Manual page 28

bandwidths up to 150 MHz and video resolutions up to 1080p and WXGA.
The built-in High-bandwidth Digital Content Protection (HDCP) decryption engine secures the
digital link for transmission of valuable high-definition video and audio. Built-in HDCP
self-test engine simplifies manufacturing testing.
HDMI Transmitter will pull high HDMI_PLUG_POWER (pin 18 in connector) when the cable
is connected. LCD Controller will pull high HDMI_HPD (pin 19 in connector) to info the
HDMI transmitter that the receiver is ready. The HDMI transmitter sends the video & audio to
MT5371 via 3 Data TMDS pairs & 1 CLOCK TMDS pairs.
HDMI
Connector
ATSC+NTSC
Combo Tuner
D. Audio
When the Antenna receive the analog TV signal and modulate it to the CVBS signal which can
be recognized by the video decoder and SIF audio signal output to the sound decoder in the
MT5371.
When the Antenna receive the digital TV signal, RF signal will be converted to IF signals and
the IF signals will be modulated to the transport bitstream by MT5112. The MT5371 receives
bitstream input in TS format, and then separates the TS into audio and video PES, analyzing the
PES header, and transferring the PES to the audio and video decoders.
The MT8291 is a highly integrated stereo audio CODEC. The MT8291 performs stereo
analog-to-digital and two digital-to-analog conversions with single-ended analog voltage input
and output. It's up to 24-bit serial values at sample rates up to 192 kHz. A 7:1 stereo input
multiplexer and an automatic level control are included.
The three analog audio sources are put into MT8291 which first select the sources and do the
stereo analog-to-digital conversion with single-ended analog voltage input Sampled data is
transmitted through the serial audio interface at various rates from 32 kHz to 192 kHz.
The serial audio signals that coming from MT8291 are put into MT5371 for DSP and audio
effect processing. The serial audio signals output from MT5371 go into the MT8291 for doing
digital-to-analog conversion and then put analog audio signals into the IC YDA138. Two DAC
outputs from MT8291 reach 2Vrms in a 12V supply environment including a headphone, two
left/right line outputs with volume gain/attenuation from -127 dB to +12 dB and digital
de-emphasis function.
ViewSonic Corporation
HDCP
EEPROM
MT5112
(Demod.)
CVBS / SIF
MT537X
System
EEPROM
25
Confidential - Do Not Copy
LCD Module
Flash
DDR
SDRAM
DDR
SDRAM
N3735w-1M