The purpose of this document is to define the operation of 17MB27 chassis, capable of driving 15” and
19” TFT LCD panels. It is aimed to provide information to engineering staff to understand the operation
and specs of the TV. The other related technical documents are given in Table1:
Title
1 17MB27 schematics
2 IR receiver and LED display board schematics
3 Keypad board schematics
4 DVD module card schematics
5 DVB-T module card schematics
Table1.1: Related documents
2 GENERAL DESCRIPTION
The system is a low to mid end; 15” and 19” TFT TV solution basically for EU market with VCT4913G
microcontroller / video audio processor chip on a 2-layer PCB. Since the target market is EU, the first
release of the TV will support PAL/SECAM B/G/D/K/I/L/L’.
The target panels are 15” 1024x768 and 19”w 1440x900 TFT-LCD panels. A DVD loader is used to read
DVD content and a DVB-T module card is used to support DVB-T. 15” TV will use 12V/4.16A DC
adapter; 19” TV will use 12V/5.83A DC adapter.
Inputs
• 1xTuner (both analog and DVB-T)
• 1xDVD
• 1xScart
• 1xPC (VGA) (optional) (supports also YPbPr)
• 2xHDMI (optional)
• 1xBack AV (optional)
Outputs
• Speaker (stereo, 2x16 , 2x2Watt)
• Headphone (stereo) (optional)
• Audio line out (stereo) (optional)
• DVD/DVB-T coaxial SPDIF out(optional)
General default features
• Multi System Reception: PAL-SECAM BG-DK-I/I’-L/L’
• Menu system (multi language)
• 100 program storage locations
• OSD (on-screen display)
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• Teletext
• IR Control (RC5 and other customer specific protocols)
• Multi System Reception : PAL-SECAM BG-DK-I/I’-L/L’
• NTSC Video Playback
• WSS (16:9 / 4:3 Aspect Ratio Auto Switch)
• Channel Type Sorting (Favorite/Sport/Music/News/Movie)
Tuning Options
• FST
• Frequency Search (Optional)
• APS (Auto Search/Name/Sort)
• Auto Search
• CATV/HYPERBAND
Keyboard
• Volume -/ +Button
• Program -/+ Button
• Menu Button
• TV / AV Button
Teletext/OSD
• Simple Text 10 Pages
• Fastext & Top Text (OPT)
• Teletext Languages (ALL)
• Character Based OSD
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• OSD Color & Transparency Selection
Electrical features
• 12V 4.16A DC / 100 - 240V AC adapter for 15” TV
• 12V 5.83A DC / 100 - 240V AC adapter for 19” TV
• <1W standby power consumption
System Building Blocks
17MB27 chassis main blocks are as follows:
•Analog Front End : VCTI (Microcontroller+Video Proccessor+Audio Proccessor+IF Demodulator+
Teletext Decoder+ OSD Generator)
• Back End : MST517a-M, MST507a-M (Scaler, Deinterlacer, OSD Generator)
Analog Front End
17MB27 main board consists of two major blocks. The first block is analog front-end and this block is
handled by VCTI chip that is highly multifunctional. VCTI performs Tuner IF demodulation, CVBS,
RGB, SVHS and audio input selection and processing. The audio processor (MSP) supports equalizer,
tone control, volume control, AVL, surround effect etc. The video processor (VSP) handles video
processing such as color standard detection and demodulation, picture alignment (brightness, contrast,
color etc.). The IC also has a teletext decoder with fastext memory. The processed video output is sent to
MST5x7A-M, scaler/deinterlacer in RGB format together with a composite sync.
The TV tuner is PLL controlled symmetrical IF output type. The IF signal is filtered by a single SAW
filter. Inter-carrier sound demodulation is performed by the system. After the SAW filter block, IF signal
is processed by VCTI IF demodulator. Audio signal is digitally filtered in the IF demodulator block. The
same IF signal is buffered and sent to DVB-T module card, tdm1300.
Since VCTI can handle all the audio processing, there is no need for additional audio processor solution on
the board. MSP has two audio inputs which are assigned to the Scart in L/R and Audio Switch L/R output.
MSP has three audio outputs which are assigned to the headphone amplifier L/R input, audio amplifier
L/R input and Audio switch L/R input. The board employs TDA2822M and TDA1308 to drive speaker
and headphone outputs, respectively. Switching control for other audio inputs and outputs (HDMI, Back
AV, PC, DVD, and DVB-T) is achieved by an I2C controlled audio switch (TEA6422).
Back End
MST5x7A-M has two ADC inputs. First ADC input is assigned to the VCTI RGB output. Other
RGB/YPbPr inputs are multiplexed for the second ADC input. HDMI receiver ANX9021 analog output,
VGA RGB input and the synchronization signals are multiplexed by a primary RGB switch (PI5V512).
MST5x7A-M has an embedded LVDS transmitter. It can be configured as either single LVDS, or dual
LVDS output.
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There are three PWM output ports. PWM0 is assigned to analog/digital dimming control for the backlight,
PWM1 is used for backlight on/off and panel logic power supply on/off control and PWM2 is used to
control PC/HDMI switch IC (PI5V512).
3 POWER CONSUMPTION
The power block diagram with the currents drawn is shown below:
4 MICROCONTROLLER PORT CONFIGURATION
PIN
NO
47 P10 MST_RESET
48 P11 TV_RXD I IDTV UART receive signal
49 P12 TV_TXD O IDTV UART transmit signal
50 P13 IRQ O IDTV interrupt request signal
51 P14 KEY I Keyboard function select
52 P15 SC_PIN8 I Scart function select
53 P16 DVD_IR_ON/OFF O DVD infrared signal on/off control
54 P17 POWCON O Standby on/off control
PORT
NAME
SIGNAL NAME TYPE FUNCTION
PROTECT
O
I
Scaler reset
Short circuit detection
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PIN
NO
PORT
NAME
SIGNAL NAME TYPE FUNCTION
55 P20 HDMI_HP_INV O HDMI hot plug signal
56 P21 CS O Switching control for Mstar bus and system I2C
62 Safety VCTI_HS O VCTI composite sync output
78 FBIN DVD_SENSE I DVD module detection
85 Vert+ TV/DVB_SW O IDTV/TV I2C and AGC switch control for tuner
27 P22 WP O Write protection control for NVM
28 P23 IR I Infrared input
Table 4.1 VCTI port configuration
5 SIDE BOARDS & CONNECTORS
5.1 Keyboard
A four-pin connector is used between 17mb27 and the keyboard:
Figure 5.1.1: Keyboard connector
KEY signal is sent directly to microcontroller ADC port and depending on the voltage level of KEY
signal, microcontroller performs one of these actions: menu, program+, program-, volume+, volume-, and
source.
SOFT_SW signal is used to switch between “power-off” and “standby” modes.
5.2 Infra-red & LED
A five-pin connector is used between 17mb27 and the LED board:
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Figure 5.2.1: LED board connector
Pin2 and pin3 carry the control signals for the LED. Pin4 carries the infra-red signal to the microcontroller.
Pin5 is used to power up the LED board.
5.3 DVB-T module board
DVB-T module board (tdm1300) is used to receive digital terrestrial broadcast signals. Three cables are
used to connect 17mb27 and tdm1300: power, data, and IF.
12V (500mA) is sent to tdm1300 by power cable:
Figure 5.3.1: DVB-T module card power connection on 17mb27
Analog RGB(YPbPr), CVBS, stereo audio, tuner control (SCL, SDA, AGC), and three GPIO port outputs
of tdm1300, together with UART ports (TV_RXD, TV_TXD, IRQ) are carried by data cable.
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Figure 5.3.2: DVB-T data connector on 17mb27
Tdm1300 board has no tuner on it. Instead, the tuner of 17mb27 is used for both analogue and digital
reception. Tuner is controlled by either the 17mb27 microcontroller (VCTI), or tdm1300 board
microcontroller. The IF (intermediate frequency) output of the tuner is sent to tdm1300 board for digital
reception.
Figure 5.3.3: IDTV IF connector on 17mb27
5.4 DVD module board
DVD module board has two parts: a loader and an electronic card. Electronic card controls the loader and
has connections with 17mb27 and DVD keypad.
Three cables are used to connect 17mb27 and DVD electronic card: power, data, and sense.
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12V (500mA) is sent to DVD electronic card by power cable:
Figure 5.4.1: DVD module board power connection on 17mb27
Y/C and/or CVBS video, stereo audio outputs and infra-red input of DVD module board is carried on data
cable:
Figure 5.4.2: DVD data connector on 17mb27
When a DVD is inserted into the loader, the DVD electronic card sends an interrupt signal (DVD_SENSE)
to the 17mb27 microcontroller:
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Figure 5.4.3: DVD_SENSE connector on 17mb27
5.5 LVDS connector
MST507A-M is used for single LVDS output and MST517A-M is used for dual LVDS output on 17mb27:
Figure 5.5.1: Single LVDS output connector on 17mb27
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Figure 5.5.2: Dual LVDS output connector on 17mb27
Panel_Vcc1 is the power input for the panel LCD module. PIN7 signal is a logic 1 or 0 signal depending
on the panel type.
5.6 Inverter
12V power, backlight on/off control, and dimming control signal are sent to the inverter board: