I znowu pojawia sie kolejne pytanie, poniewaz znalazlem w wierzy uklad scalony sluzacy jako elektroniczny potencjometr, znalazlem jego note katalogowa w ktorej jest kilka schematow katalog ten dorzucam w zalaczniku, lecz najbardziej rzuca mi sie w oczy ten schemat http://obrazki.elektroda.net/94_1151242028.gif i mam pytanie czy mozna go w jakis sposob uproscic?? Prosil bym o wszelkie propozycje.
Princeton Technology Corp.
Electronic Volume Controller IC
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
PT2253A
DESCRIPTION
PT2253A is an electronic volume controller IC utilizing CMOS Technology
specially designed for use on audio equipments. It has two (2) built-in channels
making it ideally suitable for mono and stereo sound applications. PT2253A
provides a wide frequency response range and a very low harmonic distortion to
mention a few; thereby guaranteeing a highly effective and reliable performance.
FEATURES
❒
❒
❒
❒
❒
❒
❒
❒
❒
❒
CMOS Technology
Low Power Consumption
Operating Voltage Range : Vcc = 6 ~ 12 V
(Backup Voltage is up to 4 V)
0dB to -68dB attenuation controlled by 2dB/step
2 Channels in each chip
Capable to control attenuation by a built-in oscillator and Up/Down Pin
Single Power Supply or Dual Power Supplies of (+) and (-) can be used
Wide Frequency Response Range
Very Low Harmonic Distortion
Available in 16 pin, DIP Package
APPLICATIONS
❒
❒
Audio Equipment Volume Control
Traditional VR Replacement
PT2253A v 2.6
Page 1
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
BLOCK DIAGRAM
Vcc
U/D
U/D
CK
OSC
INH
Vss
7 BITS
BIDIRECTIONAL
SHIFT REGISTER
U/D
INT
CK
5 BITS
BIDIRECTIONAL
SHIFT REGISTER
AUTO
INITIALIZE
CIRCUIT
INT
OSC
CONSTANT
CURRENT
CIRCUIT
DCO
Vcc
L-OUT1
R-OUT1
A-SW
A-SW
A-SW
A-SW
A-SW
A-SW
CK
7 BITS LATCH CIRCUIT
A-SW
7 BITS LATCH CIRCUIT
CK
L-IN1
CK
CK
R-IN1
A-SW
A-SW
A-SW
A-SW
A-SW
A-SW
A-SW
A-GND
CK
A-SW
A-SW
A-SW
A-SW
A-SW
CK
6 BITS LATCH CIRCUIT
L-IN2
6 BITS LATCH CIRCUIT
A-GND
CK
CK
A-SW
L-OUT2
R-IN2
A-SW
A-SW
A-SW
A-SW
A-SW
A-SW
R-OUT2
PIN CONFIGURATION
Vss
1
16
Vcc
L-OUT1
2
15
R-OUT1
L-IN1
3
14
R-IN1
A-GND
4
13
A-GND
L-IN2
5
12
R-IN2
L-OUT2
6
11
R-OUT2
INH
7
10
U/D
DCO
8
9
OSC
PT2253A
PT2253A v 2.6
Page 2
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
PIN DESCRIPTION
Pin Name
Pin No.
I/O
Description
Vss
L-OUT1
1
2
Power
O
L-IN1
A-GND
L-IN2
3
4
5
6
I
GND
I
O
7
I
DCO
OSC
U/D
R-OUT2
R-IN2
A-GND
R-IN1
R-OUT1
8
9
10
11
12
13
14
15
O
I/O
I
O
I
GND
I
O
Vcc
16
Power
Negative Power Supply
10dB/Step Attenuator Output
A signal applied to ‘IN’ is attenuated into 7
steps from 0dB to -60dB.
10dB/Step Attenuator Input
Analog Ground Pin
2dB/Step Attenuator Input
2dB/Step Attenuator Output
A signal applied to ‘IN’ is attenuated into 5
steps from 0dB to -8dB.
Inhibit Terminal.
At “L” level, all inputs and outputs are
disabled.
At “H” level, operation is normal.
DC Current Output Pin
RC Connecting Pin for the Oscillator
Attenuator Up/Down Control Pin
2dB/Step Attenuator Output, same as L-OUT2.
2dB/Step Attenuator Input, same as L-IN2.
Analog Ground Pin
10dB/Step Attenuator Input, same as L-IN1.
10dB/Step Attenuator Output, same as LOUT1.
Positive Power Supply
L-OUT2
INH
PT2253A v 2.6
Page 3
Revised October 1999
Princeton Technology Corp.
Electronic Volume Controller IC
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
PT2253A
FUNCTIONAL DESCRIPTION
Attenuation Setting
The Attenuation can be increased or decreased depending on the state of the U/D
Pin (either “H” or “L” Level) by actuating the built-in oscillator. When power is
applied, the attenuation is automatically set at -40dB.
When the DOWN Key is pressed, the U/D Pin goes to the “L” Level and the
oscillator is actuated in the down state. Thus, attenuation is increased.
Conversely, when the UP Key is pressed, the U/D Pin goes to the “H” Level and
the oscillator is actuated in the up state. Thus, attenuation is decreased.
Oscillation frequency (fosc) is dependent on the Cx and the Rx and is determined
by the following equation:
PT2253A v 2.6
Page 4
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
Vcc
16
Cx
Rs
OSC
9
OSC
Vcc
Rx
U/D
10
UP
DOWN
1µF
Rx = 33 K
Cx = 4.7 uF
Rs = 100 K
Vss
PT2253A has a DC Current Output Pin (DCO). The output level is divided into
13 steps. Please refer to the table below:
STEP
0
1
2
3
4
5
6
7
8
9
10
11
12
13
PT2253A v 2.6
DCO
0
I
2I
3I
4I
5I
6I
7I
8I
9I
10I
11I
12I
13I
ATTENUATION
-64dB ~ ∞
-60dB ~ -62dB
-54dB ~ -58dB
-50dB ~ -52dB
-44dB ~ -48dB
-40dB ~ -42dB
-34dB ~ -38dB
-30dB ~ -32dB
-24dB ~ -28dB
-20dB ~ -22dB
-14dB ~ -18dB
-10dB ~ -12dB
-4dB ~ - 8dB
0dB ~ -2dB
Page 5
Revised October 1999
Princeton Technology Corp.
Electronic Volume Controller IC
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
PT2253A
Current value may fluctuate depending on the IC. When high precision is
required, use a variable resistor as a load resistor.
Attenuator
Attenuator 1 attenuates 0 ~ -60dB at 10dB/step.
Attenuator 2 attenuates 0 ~ -8dB at 2 dB/step.
PT2253A v 2.6
Page 6
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
If there is the possibility of excessive voltage in the attenuator, it is recommended
that a protective diode be inserted. Please refer to the diagram below.
Vcc
Vcc
IN
Vss
Vss
Power Supply
DUAL POWER SUPPLY
+Vcc
Vcc
U/D
OSC
OSC
0V
A-GND
Vss
INH
U/D
-Vss
DCO
DC
UP
Vcc
DOWN
SINGLE POWER SUPPLY
+
Vcc
U/D
OSC
A-GND
Vss
INH
DCO
+Vcc
1/2 VDD
(A-GND)
DC
0V (Vss)
Vcc
PT2253A v 2.6
Page 7
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
Initialization When Power ON
PT2253A has the built-in auto-initializing function for the during the Power ON
period. It has the power supply on reset for the initialization of the chip. If the
power supply rises too fast, the initialization may not be fully effected. For
initialization to be fully effective, it is necessary to satisfy the following
conditions:
1. The INH Terminal must be raised simultaneously with the Supply
Voltage.
2. Initial attenuation level is -40dB
Please refer to the following diagram.
Vcc-Vss = 4.0 V
Vcc-Vss or INH TERMINAL VOLTAGE
T
1 msec
T
* If Vcc-Vss drops below 4.0 V, the auto-initializing function is actuated.
Back Up When Power OFF
When INH Pin is set at “L” Level, all input and output pins are disabled and the
current consumption is reduced to the minimum. Under this conditions, the
backup by means of a capacitor becomes possible. An example of this application
when a backup capacitor is used is shown below.
PT2253A v 2.6
Page 8
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
Vcc
VDD
10K
Vcc
PT2253A
10K
1000u
16V
Vss
INH
Vss
51K
• If Vcc-Vss drops below 4.0 V, the backup becomes impossible.
DC ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, Vcc = 12 V, Vss = 0 V and Ta = 25 oC)
PARAMETER
SYMBOL
Operating Supply Voltage
Operating Supply Current
Stand-by-Current
Vcc
Icc
ISB
Input Voltage “H” Level
(INH,U/D)
“L” Level
Attenuator 1
(10dB/step) Resistor
VIH
VIL
RATT-1
Attenuator 2
(2dB/step) Resistor
RATT-2
Max. Input Amplitude
Vin
Operating Oscillation
Frequency
DCO Output Current
fosc
PT2253A v 2.6
IDCO
CONDITION
Attenuation
Level is set to
0dB
Attenuation
Level is set to
0dB
Bias Vcc/2 = 6V
Fin=1KHz
ATT=0dB
1 Step
Page 9
TYP.
MAX.
6
-
1
-
12
3
10
0.8 x Vcc
Vss - 0.3
25
50
Vcc + 0.3
0.2 x Vcc
70
kΩ
10
20
28
kΩ
-
-
4.0
Vrms
5
Vcc=12V
INH=0V
OSC=12V
MIN.
-
10k
Hz
70
100
140
uA
Revised October 1999
UNI
T
V
mA
uA
V
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Princeton Technology Corp.
Electronic Volume Controller IC
PT2253A
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, Vcc = 6V, Vss = -6V, GND = 0V)
IN1 ~ OUT1
Characteristic
Signal to Noise Ratio
Symbol
S/N
Frequency Response
Fr
Noise Floor
NF
Total Harmonic Distortion
THD
Condition
ATT=0dB
Fin=1KHz
Vin=1.0Vrms
ATT=-10dB
Fin=1KHz
Vin=1.0Vp-p
Vin=0V,
ATT=0dB
ATT=-10dB
Fin=1KHz
Vin=1.0Vrms
Max.
97
Unit
dB
657
KHz
0.015
mv
0.010
%
IN2 ~ OUT2
Characteristic
Signal to Noise Ratio
Symbol
S/N
Frequency Response
Fr
Noise Floor
NF
Total Harmonic
Distortion
THD
PT2253A v 2.6
Condition
ATT = 0dB
Fin=1KHz
Vin=1.0Vrms
ATT=-2dB
Fin=1KHz
Vin=1.0Vp-p
Vin=0V
ATT=0dB
ATT=-2dB
Fin=1KHz
Vin=1.0Vrms
Page 10
Max.
95
Unit
dB
1820
KHz
0.022
mv
0.009
%
Revised October 1999
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Princeton Technology Corp.
Electronic Volume Controller IC
PT2253A
APPLICATION CIRCUIT 1
Dual Power Supply (L-Channel Only)
Vss
-6V
+ 4
1
LM358
_
8
2
3
10uF
VDD
+
+6V
10uF
+
Vss
L-OUT1 R-OUT1
10uF
+
INPUT
GROUND
L-IN1
A-GND
10uF
L-IN2
+
OUTPUT
Vcc
R-IN1
A-GND
R-IN2
L-OUT2 R-OUT2
INH
U/D
DCO
OSC
+
CX 4.7
PT2253A
10K
+
1N4148
100K
RS
fosc =
RS
1
(0.7)(CX)( RX)
Page 11
33K
RX
1N4148
3RX
UP
SW
PT2253A v 2.6
1uF
DOWN
SW
Revised October 1999
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
APPLICATION CIRCUIT 2
Dual Power Supply (L-Channel Only)
Vss
-6V
4
3
10uF
LM358
+
1
8
2
68pF
VDD
+6V
10uF
0.15uF
+
51K
Vss
10uF
L-OUT1 R-OUT1
+
INPUT
GROUND
L-IN1
A-GND
10uF
L-IN2
+
OUTPUT
110K
Vcc
R-IN1
A-GND
R-IN2
L-OUT2 R-OUT2
INH
U/D
DCO
OSC
CX 4.7
PT2253A
10K
1N4148
100K
RS
fosc =
RS
1
(0.7)(CX)( RX)
1uF
33K
RX
1N4148
3RX
UP
SW
DOWN
SW
Note: Since the Buffer Amp between Att-1 and Att-2 is already 10dB Voltage Gain, higher input
level may cause OP Amp’s Output Clipping. To avoid unwanted distortion, the input signal level
applied at IN-1 should not be over 1 Vrms.
PT2253A v 2.6
Page 12
Revised October 1999
Page 13
Vcc
Output
(Left Channel)
Input
(Left Channel)
10K
10K
Vcc
2
8
1
+
- LM358
4
+
100uf
C3
C1
10uf
+
10uf
+
Vcc
A-GND
R-IN1
R-OUT1
U/D
DCO
PT2253A
OSC
INH
R-OUT2
L-IN2
L-OUT2
R-IN2
A-GND
L-IN1
L-OUT1
Vss
Vcc
10uf
C2
0.1uf
Up Key
100K
10uf
C4
4.7uf
+
+
PT2253A v 2.6
+
3
2
2
IN4148
1
2
33K
IN4148
2
2
2
1
6
5
+
1uf
8
7
+
- LM358
4
Vcc (6 ~ 12V)
Output
(Right Channel)
Input
(Right Channel)
Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Electronic Volume Controller IC
PT2253A
APPLICATION CIRCUIT 3
Single Power Supply
Revised October 1999
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Princeton Technology Corp.
Electronic Volume Controller IC
PT2253A
APPLICATION CIRCUIT 4
1uf
+
68pF
2
2
2
2
2
1
Up Key
100K
+ 4.7uf
C4
Vcc
OSC
DCO
10K
Vcc
Output
(Left Channel)
Input
(Left Channel)
51K
10K
Vcc
68pF
2
0.15uf
3
8
1
+
- LM358
4
110K
+
100uf
C3
+
PT2253A
U/D
INH
R-IN2
R-OUT2
L-OUT2
L-IN2
10uf
R-IN1
A-GND
A-GND
L-IN1
10uf
C1
+
Vss
L-OUT1
R-OUT1
Vcc
10uf
+
0.1uf
+
C2
10uf
33K
IN4148
1
0.15uf
51K
IN4148
6
5
8
7
+
- LM358
4
110K
Vcc (6 ~ 12V)
Output
(Right Channel)
Input
(Right Channel)
Single Power Supply
Note: Since the Buffer Amp between Att-1 and Att-2 is already 10dB Voltage Gain, higher input
level may cause OP Amp’s Output Clipping. To avoid unwanted distortion, the input signal level
applied at IN-1 should not be over 1 Vrms.
PT2253A v 2.6
Page 14
Revised October 1999
Princeton Technology Corp.
Electronic Volume Controller IC
Tel: 886-2-29162151
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
PT2253A
ORDER INFORMATION
Valid Part Number
PT2253A
Package Type
16 Pins, DIP
PACKAGE INFORMATION
16 Pins, DIP Package
Symbol
A
750
B
65
C
PT2253A v 2.6
Dimension in Mil
55
Page 15
Revised October 1999