Philips tda9821 DATASHEETS

INTEGRATED CIRCUITS

TDA9821

Dual channel TV FM intercarrier sound demodulator

Product specification

1996 Nov 20

Supersedes data of March 1991

File under Integrated Circuits, IC02

Philips Semiconductors	Product specification

Dual channel TV FM intercarrier

TDA9821

sound demodulator

FEATURES

∙Two alignment-free PLL FM demodulators

∙Automatic second sound carrier mute

∙Mono and dual channel application

∙Low power consumption

∙Few external components required.

GENERAL DESCRIPTION

The TDA9821 is a monolithic, integrated, TV FM intercarrier sound demodulator for all FM standards.

The circuit contains two separate FM demodulators using Phase Locked Loop (PLL) reference frequency generation. The circuit requires a minimum number of external components.

QUICK REFERENCE DATA

SYMBOL		PARAMETER			CONDITIONS	MIN.	TYP.	MAX.	UNIT
VP	supply voltage (pin 14)					4.5	5.0	8.8	V
IP	supply current (pin 14)					23	30	37	mA
IM	AC peak current (pins 7 and 8)					−	−	1.5	mA
Vi(rms)	input signal (RMS value)				S + N	−	150	250	μV
					-------------- = 40 dB
					N
Vo(rms)	output signal (pins 7 and 8; RMS value)				fi = ±50 kHz	0.4	0.5	0.6	V
S + N	signal plus noise-to-noise ratio				in accordance with	64	68	−	dB
--------------	(pins 7 and 8)				“CCIR 468-3”
N
α8/7	crosstalk attenuation				f = 50 to 12500 Hz	60	70	−	dB
RR	supply voltage ripple rejection				VRR < 200 mV; f = 70 Hz	16	20	−	dB
	(pins 7 and 8)
Tamb	operating ambient temperature					0	−	70	°C
ORDERING INFORMATION
TYPE NUMBER					PACKAGE
		NAME			DESCRIPTION			VERSION
TDA9821		DIP16		plastic dual in-line package; 16 leads (300 mil); long body				SOT38-1

1996 Nov 20

2

Philips Semiconductors	Product specification

Dual channel TV FM intercarrier

TDA9821

sound demodulator

BLOCK DIAGRAM

					Rs	(1)
						9
						8	VAF1
		TDA9821
	5.5 MHz (B/G)
	1			7-STAGE
				LIMITER	VCO 1
				AMPLIFIER 1
intercarrier	5.74 MHz (B/G)
	15			7-STAGE
				LIMITER	VCO 2
				AMPLIFIER 2
		SUPPLY				7	VAF2
					mute
	13	14	12	11		10
					optional stereo	MHA424
					channel separation
				VCOref	adjustment	(1)
	VP =					Rpot
	4.5 to 8.8 V

(1) Resistor and potentiometer between capacitor and earth are inserted if adjustment of stereo channel separation is required.

Fig.1 Block diagram.

1996 Nov 20

3

Philips Semiconductors	Product specification

Dual channel TV FM intercarrier

TDA9821

sound demodulator

PINNING

SYMBOL	PIN	DESCRIPTION
IN1(B/G)	1	intercarrier input 1 at 5.5 MHz
n.c.	2	not connected
n.c.	3	not connected
n.c.	4	not connected
n.c.	5	not connected
n.c.	6	not connected
VAF2	7	audio output voltage 2
VAF1	8	audio output voltage 1
C1	9	decoupling capacitor 1
C2	10	decoupling capacitor 2
VCOref	11	VCO reference
CSTAB	12	supply voltage stabilization
GND	13	ground
VP	14	supply voltage
IN2(B/G)	15	intercarrier input 2
n.c.	16	not connected

FUNCTIONAL DESCRIPTION

The complete circuit consists of two separate channels, each consisting of a limiter-amplifier, FM demodulator and AF amplifier. Circuit operation is also described in Fig.1.

FM demodulators

The intercarrier signal is fed through external ceramic band-pass filters which are tuned to the sound carrier frequencies.

Each limiter-amplifier is AC-coupled into a

FM demodulator. The integrated FM demodulator PLLs are alignment-free. The FM demodulator outputs are amplified to 500 mV (RMS value). High amplification and DC error signals of the PLLs, which are superimposed on the FM demodulator outputs, require DC decoupling at pins 9 and 10 of the AF amplifier inputs.

handbook, halfpage
IN1(B/G)	1		16	n.c.
				IN2(B/G)
n.c.	2		15
n.c.				VP
	3		14
n.c.
	4	TDA9821	13	GND
n.c.				CSTAB
	5		12
n.c.				VCOref
	6		11
VAF2				C2
	7		10
VAF1				C1
	8		9
		MHA531

Fig.2 Pin configuration.

Stereo channel separation adjustment (optional)

Optimal stereo channel separation is achieved by adjusting VAF1 (pin 8) and VAF2 (pin 7) as follows:

1.VAF1 by a resistor in series with the DC decoupling capacitor at pin 9

2.VAF2 by a variable resistor in series with the DC decoupling capacitor on pin 10 to the same voltage as VAF1.

Normally stereo channel separation is adjusted in the stereo decoder for the B/G standard.

1996 Nov 20

4

Philips Semiconductors	Product specification

Dual channel TV FM intercarrier

TDA9821

sound demodulator

Second sound carrier mute

The output of the second FM demodulator is muted when the signal level (signal and/or noise) at pin 15 is less than typically 0.5 mV (RMS value). This avoids an incorrect stereo or dual sound identification when a mono signal is

LIMITING VALUES

transmitted. Therefore, with a mono transmission, there is no audio output at pin 7. When the signal level at pin 15 is greater than typically 1.0 mV (RMS value) mute is switched off.

In accordance with the Absolute Maximum Rating System (IEC 134).

SYMBOL	PARAMETER	CONDITIONS	MIN.	MAX.	UNIT
VP	supply voltage (pin 14)		−0.5	+9.0	V
Vi	input signal (pins 1 and 15)		−0.5	+5.0	V
ts	short-circuit time (each pin except pins 13 and 14 to		−	10	s
	be tested; one at the time)
Tstg	storage temperature
	device		−25	+125	°C
	device in packing		−25	+85	°C
Tj	junction temperature		−	150	°C
Tamb	operating ambient temperature		0	70	°C
Ves	electrostatic handling for all pins	note 1	−500	+500	V
		note 2	−4000	+4000	V

Notes

1.Equivalent to discharging a 200 pF capacitor via a 0 Ω series resistor.

2.Equivalent to discharging a 100 pF capacitor via a 1.5 kΩ series resistor.

THERMAL CHARACTERISTICS

SYMBOL	PARAMETER	VALUE	UNIT
Rth j-a	thermal resistance from junction to ambient in free air	74	K/W

1996 Nov 20

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