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INTEGRATED CIRCUITS
DATA SHEET
TDA8722 I2C-bus programmable modulator for negative video modulation and FM sound
Product specification Supersedes data of 1995 Mar 21 File under Integrated Circuits, IC02 1998 Jun 23
Philips Semiconductors
Product specification
I2C-bus programmable modulator for negative video modulation and FM sound
FEATURES • Video amplifier with clamp and white clip circuits • FM sound modulator • Asymmetrical and symmetrical RF outputs available • Symmetrical RF oscillator using only a few external components • External adjusting of modulation depth and level of the sound subcarrier • I2C-bus receiver for frequency setting and test-mode selection • One I2C programmable output port • On-chip Phase-Locked Loop (PLL) frequency synthesizer • On-chip power supply regulator • Bus switchable oscillator • On-chip Test Pattern Signal Generator (TPSG). APPLICATIONS • Video recorders • Cable converters • Satellite receivers. ORDERING INFORMATION TYPE NUMBER TDA8722T TDA8722M PACKAGE NAME SO20 SSOP20 DESCRIPTION plastic small outline package; 20 leads; body width 7.5 mm plastic shrink small outline package; 20 leads; body width 4.4 mm GENERAL DESCRIPTION
TDA8722
The TDA8722 is a programmable modulator which generates an RF TV channel from a baseband video signal and a baseband audio signal in the event of negative video and FM sound standards (PAL B/G, I, D/K and NTSC). It is especially suited for satellite receivers, video recorders and cable converters. The video carrier frequency is set exactly to the correct channel frequency by a PLL synthesizer which is programmed in accordance with the I2C-bus format.
VERSION SOT163-1 SOT266-1
1998 Jun 23
2
Philips Semiconductors
Product specification
I2C-bus programmable modulator for negative video modulation and FM sound
TDA8722
QUICK REFERENCE DATA VDDA = VDDD = 5 V; Tamb = 25 °C after the IC has reached thermal equilibrium; unless otherwise specified. SYMBOL VDDA VDDD IDD ∆m ∆P/S VRF δf Notes 1. Value depends on value of resistor R17 (see Fig.7). 2. Value depends on value of capacitor C17 (see Fig.7). PARAMETER analog supply voltage digital supply voltage total supply current typical modulation depth range typical picture-to-sound level range RF output voltage level asymmetrical on a 75 Ω load FM deviation on audio subcarrier normal mode video level (pin 19) = 0.5 V (p-p); note 1; see Fig.10 note 2; see Fig.11 frequency between 471.25 and 855.25 MHz fi = 400 Hz; V1 = 0.5 V (RMS); before pre-emphasis filter CONDITIONS MIN. 4.5 4.5 41 65 −18 77 20 TYP. 5.0 5.0 52 − − 80 25 MAX. 5.5 5.5 63 90 −10 83 30 UNIT V V mA % dB dBµV kHz
1998 Jun 23
3
Philips Semiconductors
Product specification
I2C-bus programmable modulator for negative video modulation and FM sound
BLOCK DIAGRAM
TDA8722
handbook, full pagewidth
VIDEO 19 CLAMP
ADJUST 17
AGND 18
VDDA 20
RFA 16
RFB 15
TDA8722
VIDEO AMP
VOLTAGE REGULATOR
ASYMMETRICAL OUTPUT BUFFER
CLIP AUDIO SOSCA SOSCB 1 2 3 AUDIO FM MODULATOR TPSG on balance test 13 I 2C-BUS RECEIVER 10 bits enable/ select f DIV LOGIC f ref PHASE DETECTOR enable CHARGE PUMP
AMP
TPSG
SWITCH
MIXER
PC 6 5 4 UOSCA OGND UOSCB
SDA
SCL
12
12-BIT DIVIDER (N)
PRESCALER (8)
UHF OSCILLATOR
P0
14
RF oscillator on
8 CP 7 AMP
31.25 kHz 11 VDDD 10 DGND
DIVIDER (M = 128)
4 MHz OSCILLATOR
9
XTAL
MBE401
Fig.1 Block diagram.
1998 Jun 23
4
Philips Semiconductors
Product specification
I2C-bus programmable modulator for negative video modulation and FM sound
PINNING SYMBOL PIN AUDIO SOSCA SOSCB UOSCB OGND UOSCA AMP CP XTAL DGND VDDD SCL SDA P0 RFB RFA ADJUST AGND VIDEO VDDA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 audio input sound oscillator A sound oscillator B UHF oscillator B RF oscillator ground UHF oscillator A tuning amplifier output charge pump output crystal oscillator digital ground digital supply voltage serial clock input (I2C-bus) serial data input (I2C-bus) NPN open-collector output Port asymmetrical RF output B asymmetrical RF output A modulation depth and picture-to-sound distance adjustment pin analog ground video input analog supply voltage Fig.2 Pin configuration.
SOSCA SOSCB UOSCB OGND UOSCA AMP CP XTAL 2 3 4 5
handbook, halfpage
TDA8722
DESCRIPTION
AUDIO
1
20 VDDA 19 VIDEO 18 AGND 17 ADJUST 16 RFA
TDA8722
6 7 8 9 15 RFB 14 P0 13 SDA 12 SCL 11 VDDD
MBE394
DGND 10
FUNCTIONAL DESCRIPTION The TDA8722 is a programmable modulator which can be divided into two main blocks: • A modulator for negative video modulation and FM sound TV standards • A programmable PLL frequency synthesizer. The video part of the modulator consists of a clamping circuit which sets the internal reference voltage to the bottom of the synchronizing pulse, followed by a white clip which avoids over modulation in case the video signal is too strong. Typically, the IC starts to clip the video signal when the voltage at the video input (pin 19) is >560 mV (p-p) while the normal voltage at the video input is 500 mV (p-p). .