Teac TFT IDTV, Service Manual

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2
22” TFT TV Service Manual 13/10/2004
5. AUDIO AMPLIFIER STAGE WITH AN7522
The AN7522 is an audio class-AB amplifier assembled in SIL-12 Pin Plastic Package specially designed
for sound cards application. Using this IC chassis operates as a stereo TV set. AN7522 has stand-by
feature for low stand-by power consumption and mute feature for pop noise free opening and closing the
TV set. It can deliver 2*3W without clipping at 12V/16
Ω applications.
6. POWER
The LM2576 series of regulators are monolithic integrated circuits ideally suited for easy and convenient
design of a step–down switching regulator (buck converter). All circuits of this series are capable of driving
a 3.0A load with excellent line and load regulation. Two different versions (one having a fixed output
voltage of 3.3 V, and one with 5.0 V) of this IC are used in the regulator board.
7. MICROCONTROLLER SDA55XX
7.1. General Features
• Feature selection via special function register
• Simultaneous reception of TTX, VPS, PDC, and WSS (line 23)
• Supply Voltage 2.5 and 3.3 V
• ROM version is used.
7.2. External Crystal and Programmable Clock Speed
• Single external 6MHz crystal, all necessary clocks are generated internally
• CPU clock speed selectable via special function registers.
• Normal Mode 33.33 MHz CPU clock, Power Save mode 8.33 MHz
7.3. Microcontroller Features
• 8bit 8051 instruction set compatible CPU.
• 33.33-MHz internal clock (max.)
• 0.360 µs (min.) instruction cycle
• Two 16-bit timers
• Watchdog timer
• Capture compare timer for infrared remote control decoding
• Pulse width modulation unit (2 channels 14 bit, 6 channels 8 bit)
• ADC (4 channels, 8 bit)
• UART (rxd, txd)
7.4. Memory
• Up to 128 Kilobyte on Chip Program ROM
• Eight 16-bit data pointer registers (DPTR)
• 256-bytes on-chip Processor Internal RAM (IRAM)
• 128bytes extended stack memory.
• Display RAM and TXT/VPS/PDC/WSS-Acquisition-Buffer directly accessible via MOVX
• UP to 16KByte on Chip Extended RAM (XRAM) consisting of;
- 1 Kilobyte on-chip ACQ-buffer-RAM (access via MOVX)
- 1 Kilobyte on-chip extended-RAM (XRAM, access via MOVX) for user software
- 3-Kilobyte Display Memory
7.5. Display Features
• ROM Character set supports all East and West European Languages in single device
• Mosaic Graphic Character Set
• Parallel Display Attributes
• Single/Double Width/Height of Characters
• Variable Flash Rate
• Programmable Screen Size (25 Rows x 33...64 Columns)
• Flexible Character Matrixes (HxV) 12 x 9...16
• Up to 256 Dynamical Redefinable Characters in standard mode; 1024 Dynamical Redefinable Characters
in Enhanced Mode
• CLUT with up to 4096 colour combinations
• Up to 16 Colours per DRCS Character
• One out of 8 Colours for Foreground and Background Colours for 1-bit DRCS and ROM Characters