NXP 公司的TDA8296是模擬電視和FM收音機(jī)通用數(shù)字低IF信號PLL解調(diào)器，適合所有的模擬TV標(biāo)準(zhǔn)，包括M/N, B/G/H, D/K, I, L 和 L音標(biāo)準(zhǔn)。器件通過兩個DAC還提供CVBS和 SSIF/單頻音頻。TDA8296特別適合和NXP的硅調(diào)諧器TDA1827x.配合使用。所有的處理都在數(shù)字域完成，主要應(yīng)用在TV，錄音機(jī)和PC TV。本文介紹了TDA8296主要特性和優(yōu)勢，功能方框圖，典型應(yīng)用電路圖以及多種IF輸入電路。
TDA8296：Digital global standard low IF demodulator for analog TV and FM radio
The TDA8296 is an alignment-free digital multistandard vision and sound low IF signal PLL demodulator for positive and negative video modulation including AM and FM mono sound processing. It can be used in all countries worldwide for M/N, B/G/H, I, D/K, L and L-accent standard. CVBS and SSIF/mono audio are provided via two DACs. FM radio preprocessing is included for simple interfacing with demodulator/stereo decoder backends.
The IC is especially suited for the application with the NXP Silicon Tuner TDA1827x. All the processing is done in the digital domain.
The chip has an ‘easy programming’ mode to make the I2C-bus protocol very simple. In principle, only one bit sets the proper standard with recommended content. However, if this is not suitable, free programming is always possible.
TDA8296主要特性和優(yōu)勢：
Digital IF demodulation for all analog TV standards worldwide (M/N, B/G/H, D/K, I, L and L-accent standard)
Multistandard true synchronous demodulation with active carrier regeneration
Alignment-free
16 MHz typical reference frequency input (from low IF tuner) or operating as crystal oscillator
Internal PLL synthesizer which allows the use of a low-cost crystal (typically 16 MHz)
Especially suited for the NXP Silicon Tuner TDA1827x
No SAW filter needed
Low application effort and external component count in combination with the TDA1827x
Simple upgrade of TDA8295 possible
12-bit low power IF ADC on chip running with 54 MHz or 27 MHz
Two 10-bit DACs on chip for CVBS and SSIF or audio
Easy programming for I2C-bus
High flexibility due to various I2C-bus programming registers
I2C-bus interface and I2C-bus feed-through for tuner programming
Four I2C-bus addresses selectable via two external pins
Gated IF AGC acting on black level by using H/V PLL or peak IF AGC (I2C-bus selectable)
Internal digital logarithmic IF AGC amplifier with up to 48 dB gain and 68 dB control range
Peak search tuner IF AGC for optimal adaptive drive of the IF ADC
Switchable IF PLL and IF AGC loop bandwidths
Precise AFC and lock detector
Accurate group delay equalization for all standards
Very robust IF demodulator coping with adverse field conditions
Wide PLL pull-in range up to ±1 660 kHz (I2C-bus selectable)
CVBS and SSIF or audio output with simple postfilter (capacitor only)
CVBS gain levelling stage to provide nearly constant signal amplitude during over modulation
Video equalizer with eight settings
Nyquist filter in video baseband
Excellent video S/N (typically 60 dB weighted)
High selectivity video low-pass filter for all standards
Low video into sound crosstalk
SSIF AGC
Sound performance comparable to QSS single reference concepts
AM/FM mono sound demodulator
Switchable de-emphasis
Excellent FM sound
Good AM sound
High FM Deviation mode for China
Preprocessing of FM radio (mono and stereo) with highly selective digital band-pass filter
No ceramic filter or external components needed for FM radio
FM radio available in mono
Automatic or forced mute for mono sound
Automatic or forced blank for video
Mostly digital FIR filter implementation (NSC notches and video low-pass filters)
Three GPIO pins
Power-On Reset (POR) block for reliable power-up behavior
Very low total power dissipation (typically 150 mW)
No power sequence requirement
Standby mode (typically 5 mW)
40-pin HVQFN package
CMOS technology (0.090um 1.2 V and 3.3 V)
TDA8296應(yīng)用：
TV applications
Recording
PC TV applications
圖1。TDA8296功能方框圖
圖2。TDA8296典型應(yīng)用電路圖
圖3。和TDA1827x接口的TDA8296 IF中頻輸入電路圖
圖4。TDA8296 IF輸入應(yīng)用
圖5。TDA8296 75歐姆緩沖器應(yīng)用電路
詳情請見：
http://www.nxp.com/documents/data_sheet/TDA8296.pdf