Philips TDA8822M-C1, TDA8822T-C1 Datasheet

INTEGRATED CIRCUITS

DATA SHEET

TDA8822

Universal I2C-bus programmable RF modulator

Preliminary specification			1997 Jan 08
File under Integrated Circuits, IC02

Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

FEATURES

∙5 V power supply

∙Video amplifier with clamp and white clip circuits

∙Programmable video modulation depth

∙FM sound modulator (4.5, 5.5, 6.0 and 6.5 MHz)

∙Programmable picture-to-sound ratio

∙Programmable deviation of the sound subcarrier

∙Input for modulated NICAM sound subcarrier or second frequency modulated sound subcarrier

∙Asymmetrical or symmetrical RF output buffer

∙Symmetrical RF oscillator for UHF or VHF band according to the application

∙One I2C-bus programmable output port

∙On-chip Phase-Locked Loop (PLL) frequency synthesizer for the RF carrier

∙On-chip PLL frequency synthesizer for the sound carrier

∙On-chip power supply regulator

∙On-chip I2C-bus and/or hardware controlled Test Pattern Signal Generator (TPSG) with LED driver

∙RF output switch-off during tuning.

APPLICATIONS

∙Video recorders

∙Cable converters

∙Satellite receivers

∙Set top boxes.

ORDERING INFORMATION

GENERAL DESCRIPTION

The TDA8822 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 (B/G, I, D/K, M and N standards).

Two PLL frequency-synthesizers set the picture carrier frequency and the sound subcarrier frequency to the required frequencies. These PLL frequency-synthesizers are programmed via the I2C-bus.

The I2C-bus controls these features:

∙Video modulation depth

∙Sound subcarrier modulation deviation

∙Picture-to-sound ratio.

This makes the IC suitable for multistandard applications without any adjustment into the application.

Additional features are provided like an input for the NICAM or second FM carrier, a test pattern signal generator with a LED driver and a general purpose output port.

TYPE		PACKAGE
NUMBER	NAME	DESCRIPTION	VERSION
TDA8822T	SO24	plastic small outline package; 24 leads; body width 7.5 mm	SOT137-1
TDA8822M	SSOP24	plastic shrink small outline package; 24 leads; body width 5.3 mm	SOT340-1

1997 Jan 08

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Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

QUICK REFERENCE DATA

VCCA = VCCD = 5 V; Tamb = 25 °C; in PAL B/G, PAL I, PAL D/K or NTSC; MD setting = 4; DEV setting = 2;

PS setting = 1; video input signal = 500 mV (p-p) EBU colour bars; audio input signal = 45 mV (p-p); 1 kHz sine wave; unless otherwise specified.

SYMBOL	PARAMETER	CONDITIONS	MIN.	TYP.	MAX.	UNIT
VCCA	analog supply voltage		4.5	5.0	5.5	V
VCCD	digital supply voltage		4.5	5.0	5.5	V
ICC(tot)	total supply current		−	60	72	mA
md	modulation depth adjustment	typical value for MD setting between	72.5	−	90.0	%
	range	0 and 7
P/S	picture-to-sound ratio	typical value for PS setting between	−18	−	−11	dB
	adjustment range	0 and 7
VRF	RF output voltage level	frequency between 45 and 860 MHz	77	80	83	dBμV
	asymmetrical on a 75 Ω load
fsc	sound subcarrier frequency		4.5	−	6.5	MHz
fsc	sound subcarrier frequency	for B/G, I, D/K, SC setting = 1, 2 or 3;	20	−	45	kHz
	deviation range	typical value for DEV setting between
		0 and 7
		for M, N, SC setting = 0; typical value	10	−	22.5	kHz
		for DEV setting between 0 and 7

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Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

BLOCK DIAGRAM

handbook, full pagewidth

VIDEO

AGND

VCCA

RFA RFB

	24				23	1	19	18
	CLAMP					VOLTAGE	OUTPUT
						REGULATOR	BUFFER
			TPSG
					SWITCH
		VIDEO		CLIP
		AMP.
			MD setting		TPSG
					ON/OFF
21	NICAM								20
NICAM						ADDER	MIXER		RFGND
	AMP.
				SND-IF
22				AMP.
	AUDIO		VCO	PS
AUDIO	AMP.
				setting
	DEV
						TDA8822
	setting		sound oscillator
3
			ON/OFF
PREEMPH
						RF oscillator			4
	test		test			ON/OFF			RFOSCA
	AUDIO		AUDIO		PROG.	frequency			5
2					DIVIDER				RFOSCB
	CHARGE		PHASE			setting
ACP							RF		6
	PUMP		DETECTOR
							OSCILLATOR		OGND
									7
					14 BITS
			frequency			PRESCALER			RFOSCC
			setting		PROG.				8
						DIVIDE-BY-8
					DIVIDER
									RFOSCD
									10
14			I2C-bus control						VCP
SCL			fdiv(audio)
15					test	test
SDA	I2C-BUS		fdiv(video)		VIDEO	VIDEO	test		9
	RECEIVER						LOOP
					PHASE	CHARGE
	AND						AMP.		VVT
16			in-lock flag		DETECTOR	PUMP
	LOGIC
P0			fref(video)
17
TPSG			fref(audio)
					REFERENCE	CRYSTAL			12
					DIVIDER	OSCILLATOR			XTAL
			11	13
			VCCD						MGE674
				DGND
				Fig.1	Block diagram.
1997 Jan 08					4

Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

PINNING

SYMBOL	PIN	DESCRIPTION
VCCA	1	analog power supply
ACP	2	audio charge pump output
PREEMPH	3	audio pre-emphasis network
RFOSCA	4	RF oscillator A (collector) output
RFOSCB	5	RF oscillator B (base) input
OGND	6	RF oscillator ground
RFOSCC	7	RF oscillator C (base) input
RFOSCD	8	RF oscillator D (collector) output
VVT	9	video tuning voltage output
VCP	10	video charge pump output
VCCD	11	digital power supply
XTAL	12	crystal oscillator input
DGND	13	digital ground
SCL	14	serial clock (I2C-bus) input
SDA	15	serial data (I2C-bus) input/output
P0	16	general purpose output
TPSG	17	test pattern signal generator
		input/output pin
RFB	18	RF output B
RFA	19	RF output A
RFGND	20	ground for the RF outputs
NICAM	21	NICAM input
AUDIO	22	audio input
AGND	23	analog ground
VIDEO	24	video input

handbook, halfpage
VCCA	1		24	VIDEO
ACP				AGND
	2		23
PREEMPH	3			AUDIO
			22
RFOSCA	4			NICAM
			21
RFOSCB				RFGND
	5		20
OGND	6	TDA8822	19	RFA
RFOSCC				RFB
	7		18
	8
RFOSCD			17	TPSG
VVT	9			P0
			16
VCP	10			SDA
			15
VCCD	11			SCL
			14
XTAL	12			DGND
			13
		MGE673

Fig.2 Pin configuration.

1997 Jan 08

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Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

FUNCTIONAL DESCRIPTION

The TDA8822 is a programmable RF modulator which can be divided into the following parts:

∙Video part

∙Audio part

∙RF part.

Video part

The video part provides the following:

∙The video part includes a clamping circuit which sets the internal reference voltage to the bottom of the synchronizing pulse. The modulation depth is adjusted using 3 bits of the I2C-bus programming, called MD2, MD1 and MD0. These 3 bits make 8 different values for the modulation depth possible (see Table 1).

∙After the modulation depth is set, the signal is fed through a clip control circuit that clips the video signal to avoid that the modulation depth becomes higher than 100%.

∙The video part also contains a TPSG. This TPSG generates a pattern that helps to tune the TV set to the programmed channel of the modulator. The pattern consists of a sync pulse and two vertical white bars on the screen (see Fig.3)

The TPSG is activated in two ways:

–Forcing the pin TPSG to DGND in the application (see Fig.8)

–Setting the TPSG bit to 1 via the I2C-bus, then the TPSG pin acts as an output port, sinking current to allow the indication of the use of the TPSG in the application e.g. with an LED (see Fig.9).

Table 1 Modulation depth setting (typical values)

MD		BIT		MODULATION
SETTING	MD2	MD1	MD0	DEPTH (%)
0	0	0	0	72.5
1	0	0	1	75.0
2	0	1	0	77.5
3	0	1	1	80.0
4	1	0	0	82.5
5	1	0	1	85.0
6	1	1	0	87.5
7	1	1	1	90.0

MGE675

0

5

10

15

20

25

30

35

40

45

50

55

60

65

t (μs)

Fig.3 Test pattern signal.

1997 Jan 08

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Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

Audio part

The audio part provides the following:

∙The sound subcarrier is created in an integrated VCO. The signal at the output of this VCO is fed to a stage that adjusts the picture-to-sound ratio and to the audio programmable divider.

∙The frequency of the sound subcarrier is set by programming the bits SC1 and SC0 of the I2C-bus (see Table 2). These two bits set the dividing ratio of the audio programmable divider to get the divided frequency

fdiv(audio).

∙The audio phase detector compares the

phase/frequency of the divided audio frequency fdiv(audio) and the reference frequency for the audio, fref(audio) and drives the Charge Pump (CP) that charges or discharges the audio loop filter connected between pins ACP and AGND to get the VCO oscillating to the programmed frequency.

∙fref(audio) and fdiv(audio) can be monitored on the general purpose output port during a special test mode.

∙The frequency deviation of the sound subcarrier is set using 3 bits DEV2, DEV1 and DEV0 of the I2C-bus programming (see Table 3), when a signal of 1 kHz with a level of 50 mV (p-p) is applied on the audio input pin.

∙The difference between the picture carrier level and the sound subcarrier level is adjusted using 3 bits PS2, PS1 and PS0 (see Table 4).

∙The NICAM amplifier has a constant gain, and is designed for adding a second sound subcarrier in the TV channel. This subcarrier can be either a second FM carrier for dual-sound/stereo system used in PAL B/G or a modulated NICAM carrier. The level between the picture carrier and the NICAM carrier (P/N) will depend on the input level on the NICAM input.

Table 2 Sound subcarrier frequency setting

SC SETTING		BIT			SOUND SUBCARRIER				STANDARD
	SC1			SC0	FREQUENCY (MHz)
0	0			0	4.5				M, N
1	0			1	5.5				B, G
2	1			0	6.0				I
3	1			1	6.5				D, K
Table 3 Sound subcarrier frequency deviation setting (typical values)
DEV SETTING		BIT			DEVIATION			DEVIATION (kHz)
	DEV2	DEV1		DEV0	(%)		B, G, I, D, K		M, N
0	0	0		0	40.0		20.0		10.0
1	0	0		1	45.0		22.5		11.3
2	0	1		0	50.5		25.3		12.6
3	0	1		1	56.5		28.3		14.1
4	1	0		0	63.5		31.8		15.9
5	1	0		1	71.5		35.8		17.9
6	1	1		0	80.0		40.0		20.0
7	1	1		1	90.0		45.0		22.5

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Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

Table 4 Picture-to-sound ratio setting (typical values)

	PS SETTING		BIT		P/S RATIO
		PS2	PS1	PS0	(dB)
	0	0	0	0	−11
	1	0	0	1	−12
	2	0	1	0	−13
	3	0	1	1	−14
	4	1	0	0	−15
	5	1	0	1	−16
	6	1	1	0	−17
	7	1	1	1	−18

RF part

The RF part provides the following:

∙The RF oscillator can produce any frequency used for TV transmission, from 35 to 890 MHz. The frequency range depends on the components used in the application (see Table 11).

∙The RF mixer combines the video signal, the sound subcarrier and the carrier from the NICAM input to build a baseband TV channel. This baseband signal is then mixed with the RF oscillator signal to get the RF TV channel.

∙The two signals from the RF mixer are sent to the output buffer. This output buffer can be used either as two asymmetrical outputs or as one symmetrical output.

∙The output buffer is switched-off while the PLL is not in-lock, to avoid parasitic output signal during the tuning of the RF oscillator. The in-lock information is given by the phase detector of the loop.

∙The signal from the RF oscillator is fed to the PLL which controls the picture carrier frequency. The RF signal is first divided by 8 in the prescaler, and then divided in the programmable 14-bits divider. The dividing ratio of this divider is programmed via the I2C-bus. The minimum frequency that can be synthesized is 16 MHz, and the maximum frequency is 1023.9375 MHz.

∙The divided frequency called fdiv(video) is compared to the reference frequency called fref(video) coming from the crystal oscillator and divided in the reference divider. The crystal oscillator is intended to be used with a crystal of 4 MHz.

∙The comparison between fref(video) and fdiv(video) is done in the video phase detector. The resulting signal is fed via the video charge pump to the loop amplifier, including the tuning voltage drive (33 V) inside the IC.

∙fref(video) and fdiv(video) can also be monitored on the output port during a special test mode.

∙The I2C-bus receiver and control logic includes the control of:

–Picture carrier frequency

–Sound subcarrier frequency

–Sound subcarrier frequency deviation

–Video modulation depth

–Picture-to-sound ratio

–TPSG on/off and LED drive control

–RF oscillator on/off

–Sound oscillator on/off

–General purpose output port on/off

–Test modes setting.

Software information

The transmission is made using 4 words in I2C-bus format. First the address CA has to be sent, then at least two consecutive words have to be sent, either the two words F1 and F0, or the two words C1 and C0.

The two words C1 and F1 are differentiated inside the IC by the first bit being logic 1 or logic 0 respectively.

The contents of the 4 bytes is shown in Table 5.

At the power-up of the TDA8822, the I2C-bus state is the following:

∙N13 to N0 are not fixed

∙SC setting = 1: the sound carrier is fixed to 5.5 MHz

∙MD is set to 4 (82.5%), PS is set to 1 (−12 dB) and DEV is set to 2 (50.5%)

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Philips Semiconductors	Preliminary specification

Universal I2C-bus programmable RF

TDA8822

modulator

∙T0 is set to logic 1, RF0 is set to logic 1, TPSG is set to logic 1 and P0 is set to logic 0 to select the video high impedance test mode because it is in this mode that the RF oscillator starts in the best conditions.

The TPSG bit is used to switch on or off the TPSG using the I2C-bus. It is also possible to switch the TPSG on in the application, connecting the pin TPSG to DGND. This

pin TPSG has a double function and acts as an input or as an output.

These are the two functions:

∙Output: if the TPSG is set using the I2C-bus, the

pin TPSG is used as an output open collector NPN port. This port can be used to indicate with an LED that the TPSG is on. This is especially useful in systems using an on-screen display. If the TV set is not tuned to the right channel there is an alternate indication that the TPSG is on (see Fig.9).

∙Input: if the TPSG is set with an hardware switch in the application, the TPSG pin is used as one of the inputs to select the TPSG mode (see Fig.8).

Notice that if the TPSG bit is set to logic 1 while the RF0 bit is set to logic 0, the TPSG is turned off, and the sound oscillator is off (see Table 8).

N13 to N0 are the 14 bits to set the video programmable divider ratio and then to set the picture carrier frequency following the formula: fosc = fref(video) × 8 × N,

where:

∙fref(video) is the frequency on pin XTAL divided by the reference divider ratio. For example, with a 4 MHz crystal connected to

pin XTAL, fref ( video)	=	4-----------------------000 000	= 7812.5 Hz
		512

Table 5 Contents of programming words

∙N is the programmable divider ratio:

N = N13 × 213 + N12 × 212 + ... + N1 × 2 + N0

∙fosc is the RF oscillator frequency.

DEV2, DEV1 and DEV0 are the bits to set the sound subcarrier frequency deviation (see Table 3).

PS2, PS1 and PS0 are the bits to set the picture-to-sound ratio (see Table 4).

MD2, MD1 and MD0 are the bits to set the modulation depth (see Table 1).

SC1 and SC0 are the bits to set the sound subcarrier frequency according to Table 2.

RF0 is a bit that controls the RF oscillator on/off. In normal mode, it should be set to logic 1. If the modulator is not used and may create some interferences with other signals in the application, it should be set to logic 0

(see Table 6).

Notice that if the bit RF0 is logic 0 while the bit TPSG is logic 1, then the RF oscillator is still running, but the sound oscillator is off, and the TPSG is also off (see Table 8).

The bit P0 controls the output port P0, which is an open collector NPN port, able to drive up to 10 mA

(see Table 7).

T0 is a bit used for test purposes. If this bit is set to logic 0, the IC operates in normal configuration. If it is set to logic 1, then the use of bits TPSG, RF0 and P0 is changed to select 1 of the 8 test modes as explained in Table 9.

	BYTE	MSB							LSB	ACKNOWLEDGE BIT
		BIT 7	BIT 6	BIT 5	BIT 4	BIT 3	BIT 2	BIT 1	BIT 0
	Address byte CA	1	1	0	0	1	0	1	0	ACK
	F1: frequency	0	TPSG	N13	N12	N11	N10	N9	N8	ACK
	byte 1
	F0: frequency	N7	N6	N5	N4	N3	N2	N1	N0	ACK
	byte 0
	C1: control byte 1	1	DEV2	DEV1	DEV0	PS2	PS1	PS0	0	ACK
	C0: control byte 0	MD2	MD1	MD0	SC1	SC0	RF0	P0	T0	ACK

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