Panasonic AN8946SB Datasheet

ICs for TV

AN8946SB

FM demodulation IC for BS/CS broadcasting

■ Overview

The AN8946SB is a 5 V single power supply and low
power consumption FM demodulation IC for BS/CS broad­casting. It features PLL · FM demodulation, 2nd IF AGC
amp., AGC detection and AFC (applicable to both mean
value and keyed types).

■ Features

• 5 V single power source

• Low power dissipation (typ. 170 mW)

• S/N 65 dB or more

• Inter-modulation interference ratio: 50 dB or more

• AGC amp built in (Reduction range: 55 dB)

• Adjustment-free VCO coil

■ Applications

• BS/CS tuner, television

■ Block Diagram

14

0.1±0.1

(0.4)

1

7.2±0.3

9.3±0.3

SSOP028-P-0375A

28

15

+0.1

–0.05

0.2

0.3±0.1

0.8

0.9±0.1 0.9±0.1

Unit : mm

11.6±0.3

2.05±0.2

28

27

AFC
amp.

Key Comp.

Latch

1

2

26

3

25

4

CC

V

5 V

Reg. out

24

AGC
amp.

23

22

GND

21

20

IF

amp.

2.6 V
19

18

DC

amp.

17

16

DC

amp.

15

PD

11

Loop
amp.

12

13

14

VCO REG

5

CC

5 V

V

6

GND

7

8

GND

Video

amp.

9

10

1

AN8946SB ICs for T V

■ Pin Descriptions

Pin No. Description

1 Key pulse input
2 AFC output L
3 AFC output H
4V

(VCO, AFC system)

CC2

5VCO1
6 GND3 (VCO system)
7 VCO2
8 GND2 (Main)

9 Loop amp. output
10 Video amp. input
11 Video amp. output
12 Free-run frequency adjustment
13 Loop amp. input 1
14 Loop amp. input 2

Pin No. Description

15 AFC adjustment
16 AGC output 2
17 AGC output 1
18 AGC adjustment
19 IF amp. output
20 Regulator output
21 V

CC1

(Main)
22 GND1 (AGC amp., regulator system)
23 IF amp. input 2
24 IF amp. input 1
25 AFC output R
26 AFC LPF2
27 AFC LPF1
28 Key pulse LPF

■ Absolute Maximum Ratings

Parameter Symbol Rating Unit

Supply voltage V
Supply current I
Power dissipation P
Operating ambient temperature
Storage temperature

Note) 1. Be carefl for static electricity damage of pin 1 to pin 5, pin 7, pin 21, pin 26 and pin 28.

: Except for the operating ambient temperature and storage temperature, all ratings are for Ta = 25°C.

2. *

*

*

CC

CC

D

T

opr

T

stg

5.6 V
50 mA

280 mW

−20 to +75 °C

−55 to +150 °C

■ Recommended Operating Range

Parameter Symbol Range Unit

Supply voltage V

CC

4.5 to 5.5 V

2

ICs for TV AN8946SB

■ Electrical Characteristics at Ta = 25°C

Parameter Symbol Conditions Min Typ Max Unit

Total circuit current I
IF amp. maximum gain GIF

IF amp. minimum gain GIF

Loop amp. gain G
Video amp. gain G
VCO control sensitivity β f = 402.78 MHz 3 7 39 41 MHz/V
Signal to noise ratio S/N

(C/N = ∞) LPF 4.2 MHz, HPF 10 kHz
Inter-modulation interference IM

ratio (2nd) fS = 5.7272 MHz
Inter-modulation interference IM

ratio (3rd) fS = 5.7272 MHz
AFC dead-band width BW
AFC output maximum voltage V
AFC output minimum voltage V
AGC output maximum voltage 1 V
AGC output minimum voltage 1 V
AGC output maximum voltage 2 V
AGC output minimum voltage 2 V

AGC1HVCC

AGC1L

AGC2HVCC

AGC2L

AGC SW level Pin

Key pulse input maximum voltage V
Key pulse input minimum voltage V
Noise amplitude V

Pin 12 voltage V

Pin 15 voltage V

V

TOT

max

min

LA

VA

max

2

3

AFC

AFCHVCC

AFCLV2

= 5 V 28 34 40 mA

CC

PIFIN = −60 dBm, f = 402.78 MHz 22 25 28 dB
V

= 5 V

17

PIFIN = 0 dBm, f = 402.78 MHz −29 −25 dB
V

= 0 V

17

PLA in = −30 dBm, f = 1 MHz 22 24 26 dB
PVA in = −10 dBm, f = 1 MHz 6.5 7.0 7.5 dB

PIFIN = −30 dBm, 100%W, weighting 62 67  dB

PIFIN = −30 dBm, fC = 3.58 MHz 40 6 0  dB

PIFIN = −30 dBm, fC = 3.58 MHz 40 6 0  dB

Pin 2: Low, Pin 3: High 310 360 420 kHz

− V3 value, f = 402.78 MHz  00.5V

value, f = 402.78 MHz  0.1 0.5 V

− V17 value, PIFIN = −70 dBm  00.2V

PIFIN = +10 dBm  0.3 0.5 V

− V16 value, PIFIN = −70 dBm  00.2V

PIFIN = +10 dBm  0.3 0.5 V
f = 402.78 MHz, PIFM = −50 dBm −39 −35 −31 dBm

SW

Input level at V
DC measurement 0.35  V

KEYH

DC measurement 0.1 V

KEYL

f = 402.78 MHz with no modulation  4 10 mV[p-p]

N

= 2.5 V

16

and with de-emphasis
Measure it at Video out pin.

Voltage to get V

12

= 0 V, V2 ≤ 1 V, 1.0 1.35 1.7 V

17

V3 ≥ 4 V with no PIFIN .
Voltage to be AFC center with no PIFIN , 1.03 1.15 1.27 V

15

V

= 0 V, f

17

= 402.78 MHz

VCO

• Design reference data

Note) The characteristics listed below are theoretical values based on the IC design and are not guaranteed.

Parameter Symbol Conditions Min Typ Max Unit

IF amp. frequency characteristic f
IF amp. NF NF
Loop amp. frequency characteristic f
Loop amp. phase PH

3 dB down frequency 600 700  MHz

CIF

f = 402.78 MHz, V

IF

3 dB down frequency 200 250  MHz

CLA

f = 1 MHz to 20 MHz ±5 ±10 °

LA

= 5 V  12 15 dB

17

3