Transcript
ICs for Cassette, Cassette Deck
AN6291, AN6291S Dual dbx II Noise Reduction System ICs AN6291
1.2±0.25
0.5±0.1 2.54
26.7±0.3
1.0±0.25 3.3±0.25 + 0.1 .05
0.35 – 0
3 ~15˚
10.16±0.25
22-Lead DIP Package (DIP022-P-0400A)
AN6291S
22 21 20 19 18 17 16 15 14 13 12
0.3 7.2±0.3 9.4±0.3
22-Lead SOP Package (SOP022-P-0375)
15.3±0.3
1 2 3 4 5 6 7 8 9 10 11
0.15 0.925
1.09
Unit : mm
0.4±0.25
VCC (opr) =1.8V to 14V
22 21 20 19 18 17 16 15 14 13 12
4.7±0.25
1.27
■ Features • Wide dynamic range : 110dB • Low operating voltage : VCC (min.) =1.8V • Fewer external components • Adjustment : only one • Low power consumption • Wide operating supply voltage range :
Unit : mm
1 2 3 4 5 6 7 8 9 10 11 8.6±0.3
0.1±0.1
The AN6291 and the AN6291S are the single chip ICs suitably developed for noise reduction of dbxII type and used for stereo operation. They can be used for U.S. sound multiplex TV. 1.8V low voltage operation enables to apply for battery-operated equipment to the Hi-Fi deck. Package is available for 22-pin DIL plastic and 22-pin SOP package. Equipment can be minitualized and high integration.
2.0±0.2
■ Overview
ICs for Cassette, Cassette Deck
AN6291, AN6291S ■ Block Diagram VCC
NC
RMS IN–B
TIMING –B
CCA IN–B
CAP 1–B
CAP 2–B
VOUT– B
22
21
20
19
18
17
16
15
ON – OFF –B I TIME ENCODE 14
13
12
VCC –
RMS
OP Amp.
CCA
+
Current Source
Logic
Timing Current
+
RMS
OP Amp.
CCA
–
Bias GND SUB 1
2
3
4
5
6
7
8
ADJ
GND
RMS IN– A
TIMING –A
CCA IN– A
CAP 1– A
CAP 2– A
VOUT– A
9 ON – OFF –A
■ Pin Descriptions Pin No.
Pin Name
Pin No.
Pin Name
1
Adjustment of timing current
12
ENCODE
2
GND
13
I TIME
3
RMS IN-A
14
ON-OFF-B
4
TIMING-A
15
VOUT-B
5
CCA IN-A
16
CAP-2-B
6
CAP-1-A
17
CAP-1-B
7
CAP-2-A
18
CCA IN-B
8
VOUT-A
19
TIMING-B
9
ON-OFF-A
20
RMS IN-B
10
N.I.
21
NC
11
DECODE
22
VCC
10
11
N.I.
DECODE
ICs for Cassette, Cassette Deck
AN6291, AN6291S
■ Absolute Maximum Ratings (Ta=25˚C) Symbol
Rating
Supply Voltage
Parameter
VCC
14.4
Unit
Supply Current
ICC
5
mA mW
V
Power Dissipation (Ta=75˚C)
PD
100
Operating Ambient Temperature
Topr
–20 ~ + 75
˚C
AN6291
Tstg
–55 ~ + 125
˚C
AN6291S
Tstg
–40 ~ + 125
˚C
Storage Temperature
■ Electrical Characteristics (VCC=3V, Ta=25˚C) Parameter Input/Output Characteristics/ENCODE Mode
Input/Output Characteristics/DECODE Mode
Maximum Output Voltage
Symbol
–2
0
+2
VIN= –40dB, f=1kHz
–23
–20
–17
VOD –1
VIN = + 10dB, f=1kHz
17
20
23
VOD –2
VIN=0dB, f=1kHz
–2
0
+2
VOD –3
VIN= –20dB, f=1kHz
–44
–40
–36
80
150
200
450
THDD
Noise Output Voltage
ENCODE Mode
VNOE
DECODE Mode
VNOD
Difference Between Channels
ENCODE Mode
CDE
DECODE Mode
CDD CT SVRR ICC
Input/Output Characteristics/dbx OFF Mode
VOFF
Total Harmonic Distortion/dbx OFF Mode
THDOFF
Output Noise Voltage/dbx OFF Mode Note) 0dB= 20mV= –34dBV
max.
VIN = 0dB, f=1kHz
VOME
Quiescent Current
typ.
VOE –3
VOMD
Ripple Rejection Ratio/DECODE Mode
7.5
VOE –2
DECODE Mode
Crosstalk/ENCODE Mode
min.
VIN = + 20dB, f=1kHz
ENCODE Mode
Total Harmonic Distortion/DECODE Mode
Condition
VOE –1
VnOFF
THD=1%, f=1kHz
10
Unit
12.5 dB
dB
mV
VO = + 14dB, f=1kHz
0.15
0.3
%
Input Short A-weight
100
200
3
6
µV
–1.2
0
1.2
–1.2
0
1.2
50
60
VIN= 0dB, f=1kHz Measuring channel : Short Another channel : Output 200mV, f=1kHz f=60Hz, V=100mV, Input Short VCC =3V, Input Short VIN = + 20dB, f=1kHz VIN = + 20dB, f=1kHz Input Short, A-weight
40 17
dB dB dB
55 1.8
3.2
mA
20
23
dB
0.3
1
%
10
20
µV
ICs for Cassette, Cassette Deck
AN6291, AN6291S
0 –20 VOUT –40 –60 –80 Vno –100 –120 –140
+20
VCC= 3V Vin= –34dBV
100
1k
VCC= 3V Vin= – 34dBV
0 –20
VOUT
–40 –60 –80 –100 –120
1.0
0.5
0 20
10k 20k
1.5
Vno
–140 20
100
Frequency f (Hz)
1k
10k 20k
20
100
Frequency f (Hz)
THD – f (Decoder mode)
1k
10k 20k
Frequency f (Hz)
VOUT, THD –VIN (Encoder mode)
VOUT, THD–VIN (Decoder mode)
–10
2.0
VCC = 3V Vin= – 34dBV
VCC= 3V f= 1kHz
–0
VCC= 3V f= 1kHz
1.5
–50
1.0 THD
–60
0 20
100
1k Frequency f (Hz)
10k 20k
–70 –100
0.5
–80
–60
–40
–20
Input Voltage VIN (dBV)
0
0 +20
OU
T
2.0 –40
1.5 –60 1.0 –80 0.5 THD –100 0 –70
–60
–50
–40
–30
Input Voltage VIN (dBV)
–20
Total Harmonic Distortion THD (%)
–40
–20
V
OU
2.0
Output Voltage VOUT (dBV)
0.5
–30
Total Harmonic Distortion THD (%)
1.0
V
1.5
T
–20 Output Voltage VOUT (dBV)
Total Harmonic Distortion THD (%)
THD – f (Encoder mode) 2.0
Total Harmonic Distortion THD (%)
VCC= 3V Vin= – 34dBV
VOUT, Vno– f (Decoder mode) Output Noise Voltage Vno, Output Voltage VOUT (dB)
Output Noise Voltage Vno, Output Voltage VOUT (dB)
VOUT, Vno– f (Encoder mode) +20
ICs for Cassette, Cassette Deck
AN6291, AN6291S
■ Application Circuits 1 Switching circuit of recording/playback +VCC E 0.1µF –
3.3kΩ
10µF
+ D
E
330pF
+ 0.47µF
2SC1327
+
0.033µF
51kΩ –
SW1e +
22µF
10µF
+
1kΩ
6800pF
–
Output –B
– 0.01µF
15kΩ 1kΩ
10kΩ
150kΩ
6800pF
–
0.1µF 4.7kΩ 33kΩ 6.8kΩ
15kΩ
SW1b
0.0033µF
0.0033µF
270k
33kΩ
SW2a
OFF ON
560Ω
–
15kΩ
+
10µF
SW1a
0.1µF
2700pF
D
330Ω
Input –B
D
E
*2
21
20
19
18
17
16
15
RMS– B
CCA– B
OP Amp.– B
RMS – A
CCA– A
OP Amp.– A
14
13
9
10
12
Logic
22
Current Source
SUB 1
2
3
4
5
6
7
8
–
2k (B)
+
10kΩ
330pF
0.0033µF
0.0033µF
270kΩ
51kΩ
–
1µF
6800pF
1kΩ 0.033µF
2SC1327 1µF 4.7kΩ 33kΩ 6.8kΩ
– +
330Ω
15kΩ
0.47µF 6800pF
D –
SW1d
2700 pF SW1e
3.3kΩ
33kΩ 0.1µF
15kΩ
+
22µF
10µF
–
150kΩ
11 +
*1
+
10µF
0.01µF
Output –A
ON
– 560Ω OFF
SW2b
51kΩ
E
+
0.1µF
E D Input –A
Logical condition of recording/playback Pin11
Pin12
Mode
VCC
Open
DECODE
Open
VCC
ENCODE
VCC
VCC
OFF
* 1 Signals of 1kHz, 20mV are applied to the input of both channels at the same time, sinking current into the Pin13 should be adjusted to 15µA±5%. Standard value at VCC=3V is about 1kΩ. * 2 External circuit should not be connected with Pin21. Connected in the IC. * 3 Users should follow the latest technical information from dbx company. Constant number might be changed. Note 1) All the resistors and the capacitor with the mark should be used in the error less than ±5%. Note 2) S1a~ S1e : Switch record, playback (Above figure shows “PLAYBACK” mode). Note 3) S2a~ S2b : dbx ON-OFF switch (Above figure shows “ON” mode).
ICs for Cassette, Cassette Deck
AN6291, AN6291S 2 Playback exclusive circuit (Designed noise at dbx OFF mode to be small)
+VCC
0.033µF 1kΩ
4700pF
0.47µF
Input –B
–
+
10kΩ
10µF +
150Ω
0.01 µF
560Ω
Output –B
–
–
–
+
+
0.33µF
–
21
16kΩ
4.7kΩ
16kΩ
*2 NC 22
+
0.022µF
10µF
20
19
RMS– B
18
17
16
15
14
dbx ON– OFF Open “ON”
(
)
12
OP Amp.– B
CCA– B
Logic
1
2
RMS–A
3
4
*1 2kΩ (B)
OP Amp.– A
CCA–A
5
6
7
8
9
10µF 10kΩ
–
+ 0.33µF – –
+
1kΩ
0.47µF
16kΩ
11
+ –
1µF
68µF 150Ω
+
0.022µF
16kΩ +
10 4.7kΩ
Sub
–
+ –
13
Current Source
Input –A
10µF
1kΩ 68µF
4700pF
+
–
10µF 560Ω
Output –A 0.01µF
0.033µF
* 1 Signals of 1kHz, 20mV are applied to the input of the both channels, adjust sinking current into the Pin13 to 15µA±5% Standard value at VCC=3V is about 1kΩ. * 2 External circuit should not be connected with the Pin21. Connected in the IC. * 3 Users should follow the latest technical information from dbx company. Constant number might be changed. Note 1) All the resistors and the capacitor with the mark should be used in the error less than ±5%. Note 2) Impedance of the input signal source should be less than 100Ω.
ICs for Cassette, Cassette Deck
AN6291, AN6291S
■ Effect of dbxII Noise Reduction System (Without noise reduction system) +20dB Fortissimo +10dB
Playback
Output
60 ~ 70dB
Magnetron tape
100dB
Recording
DC range
+10dB
0dB Input Level
Fortissimo (large sound) distortes due to magnetron saturation
Magnetron saturation level Distortes
– 60dB
Z-
– 60dB Noise level
Pianissimo
Even if input width is 100dB, width 60-70dB is playbacked in output.
Noise
Pianissimo (small sound) is erased by the hysnoise of tape
– 80dB
(When dbx II System is ON)
+10dB Compressed to 1/2 by dB
Magnetron tape
Recording (Encode)
100dB Input level
0dB
Expanded to 2 times by dB
– 40dB
o sim nis se Pia rea c n I – 80dB
+20dB
Pian issim Dec o reas e– 80d Noi B se l eve l
D range is expanded in equal value as fortissimo is increased and pianissimo is decreased its level, and they are playbacked.
100dB of input range is playbacked as well
Small sound is playbacked, too.
Noise Fortissimo is decreased less than saturation level and pianissimo is increased more than noise level. Thus they are recorded.
Large sound is playbacked without distortion
Output
Increase mo Fortissi
D range
Decre ase simo
Fortis
Playback (Decode)
+20dB
Noise level is decreased more than by 30dB at the playback mode (Improvement of S/N ratio)
■ Cautions (1) When users use the AN6291 and the AN6291S, contract should be made between the dbx Technology Licensing. dbx licence and trademark should be contacted with the following. the U.S.A. : dbx Technology Licensing JAPAN Office : dbx Technology Licensing 433 California Street, Third Floor Tel : 03-3378-0915 San Francisco, California 94104 Fax : 03-3374-5191 Tel : 415-765-2801 Fax : 415-765-2141 (2) Capacitor between the Pin6 – 7 and Pin16 –17 is used to cut DC current. When leakage of DC current is large, encode and decode characteristics is not right value, capacitor's leakage should be as minimum as possible. (3) The AN6291 is a low power consumption current type. So effection of wiring resistance is small and oscillation character-ist of pattern location is good, however, when impedance of the input pin is high, wiring should be shorter because it is easily effected by external noises.
