SILAN SC9235

Silan
Semiconductors SC9235
ELECTRONIC VOLUME
DESCRIPTION
The SC9235 and SC9235S are an optimum CMOS IC which
SOP-16
has been designed for electronization of volume control of audio
equipment, etc.
FEATURES
* Attenuation can be controlled from 0dB to -78dB by up, down
input.
* This IC have 20dB tap for loudness circuit.
DIP-16
* This IC features a built-in DC output circuit (7 level) for volume
level meter.
* Polysilicon resistors enables low-distortion, high-performance
volume systems.
* Volume level remains in backup mode with low current
consumption.
ORDERING INFORMATION
* Package is DIP16 and SOP16.
PIN CONFIGURATION
VSS
1
16
VDD
OUT-1
2
15
OUT-2
IN-1
3
14
IN-2
TP-1
4
13
TP-2
GND-1
5
12
GND-2
UP
6
11
DC-OUT
7
10
INH
OSC
8
9
INT
DIP-16 Package
SC9235S
SOP-16 Package
BLOCK DIAGRAM
VSS
1
16
VDD
OUT-1
2
15
OUT-2
IN-1
3
14
IN-2
TP-1
4
13
TP-2
GND-1
5
12
GND-2
11
DC-OUT
10
INH
9
INT
SC9235
DN
SC9235
DECODER
D-A
CONVERTER
UP
6
DN
7
UP/DOWN
COUNTER
CONTROL
OSC
8
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
1
2000.12.31
Silan
Semiconductors SC9235
ABSOLUTE MAXIMUM RATINGS(Ta=25°C)
Characteristic
Symbol
Value
Unit
Supply Voltage
VDD
-0.3 ~15
V
Input Voltage
VIN
-0.3V ~ VDD+0.3V
V
Power Dissipation
PD
300
mW
Operating Temperature
Topr
-40 ~ +85
°C
Storage Temperature
Tstg
-55 ~ +150
°C
ELECTRICAL CHARACTERISTICS(Unless otherwise specified, Ta = 25k,
Parameter
VDD = 9V)
Symbol
Test Conditions
Min
Typ
Max
Unit
Operating Supply Voltage
VDD
Ta=-40 ~ 85°C
4.5
9.0
12
V
Operating Supply Current
IDD
No load,fosc=20Hz
--
0.3
1.0
μA
Backup Voltage
VQD
2.0
--
12
V
Backup Current
IQD
--
0.01
1.0
μA
0.7VDD
--
VDD
0
--
0.3VDD
VIH=VDD
-1
--
1
VIL=0V
-1
--
1
Input Voltage
Input Current
"H" Level
VIH
"L" Level
VIL
"H" Level
IIH
"L" Level
IIL
INH ="L"
All input pin
INH input pin
V
μA
Pull Up Resistor
RUP
UP , DN , INT Input pin
23
47
71
kΩ
Volume Resistor
RVR
Between INGND resistor
31
44
58
kΩ
Analog Switch ON Resistor
RON
Analog switch ON resistor
--
500
800
Ω
--
0
±2.0
dB
--
0
±3.0
%
Attenuation Error
ΔATT
Balance Between Left And Right
ΔRVR
Total Harmonic Distortion
THD
FIN=1kHz
0dB
--
0.01
--
%
ATTMAX
VIN=1Vrms
∞dB
--
100
--
dB
Cross Talk
C.T
RL=100kΩ
--
100
--
dB
Output Noise Voltage
VN
Rg=600Ω
--
2.0
--
μVrms
--
20
--
Hz
Maximum Attenuation
OSC Frequency
fOSC
-Volume resistor error between
left and right
Cx=2.2μF, Rx=33kΩ
0dB
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
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2000.12.31
Silan
Semiconductors SC9235
PIN DESCRIPTION
Pin No.
Symbol
Pin Name
1
Vss
Negative power supply pin
16
VDD
Positive power supply pin
2
OUT-1
15
OUT-2
3
IN-1
14
IN-2
4
TP-1
13
TP-2
5
GND-1
12
GND-2
6
UP
Description
Power Supply terminal
Volume output pins
Volume circuit
Volume input pins
OUT
IN
Tap output pins for loudness
TP
GND
Analog ground pins
Volume up, down control input pin.
Volume up input pin
The 1 step / 1 push volume is controlled by pushing
the Up or Down key . If the key has been pushed
7
DN
continuously, the continuous volume control.
Volume down input pin
These two input pins have built-in pull-up resistor.
Oscillation pin.
8
OSC
Oscillation pin
Oscillator circuit consist of C.R connection.
Oscillation is executed while key is pushed.
Input pin for setting initial volume level volume level
9
INT
Initializing pin
set to 46dB by "L" input.
This input pin has built-in pull-up resistor.
Back up mode input pin.
10
INH
Inhibit terminal
Internal all operation is stopped by "L" input, and
volume level remains with low current consumption.
DC output pin for volume level meter.
11
DC-OUT
DC output pin for level meter
DC voltage which is corresponded to volume step is
generated.
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
3
2000.12.31
Silan
Semiconductors SC9235
FUNCTION DESCRIPTION
1. VOLUME CIRCUIT
Volume circuit consist of ladder resistor and analog switch.
Tap for loudness is connected to step 10 (20dB).
Attenuation is as follows when resistor (3.9kΩ) is connected between TP pin and pin.
*
*
Equivalence circuit
Volume step and attenuation
(Attenuation is as follows when resistor (3.9kΩ) is
connected between TP pin and GND pin.)
OUT
IN
Step
Attenuation
Step
Attenuation
0
0(dB)
16
32(dB)
1
2
17
34
2
4
18
36
3
6
19
38
4
8
20
40
5
10
21
42
6
12
*22
46
S10
7
14
23
50
S11
8
16
24
54
9
18
25
58
10
20
26
62
11
22
27
66
12
24
28
70
13
26
29
74
14
28
30
78
15
30
31
∞
S0
S1
S2
28.5kΩ
S9
TP
20.25kΩ
S30
GND
S31
* Step 22 (46dB) initial value.
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
4
2000.12.31
Silan
Semiconductors SC9235
2. VOLUME UP, DOWN CONTROL CIRCUIT
Volume up, down control is executed by UP , DN key input.
* The 1 step / 1 push volume is controlled by "L" level of UP , DN key.
* If UP , DN key is input "L" continuously, volume level is changed continuously.
* Timing of key input
UP / DN INPUT
VOLUME LEVEL
t
T
a
(fOSC=20Hz)
Note: t : Prevent time for chattering 2.21/fosc(110ms)
T: Switching time to automatic mode 101/fosc(500ms)
a : Up,Down speed 21/fosc(100ms)
foscCx•Rx(Hz) : Rx=12~220k
3. DC OUTPUT CIRCUIT FOR VOLUME LEVEL
DC output for volume level meter is internally connected to D−A converter (R/2R type).
8 stage output voltage which is corresponded to volume level is generated.
Because output impedance ≈ 22kΩ (typ.) is high, If input impedance of next setting level meter IC is low,
set to Buffer.
* Volume step and Output voltage
Equivalence circuit
2R
DC-OUT
2R
2R
R
Step
Attenuation(dB)
Output Voltage(V)
0~3
0~6
7/ 8 VDD
4~7
8 ~ 14
6/ 8 VDD
8 ~ 11
16 ~ 22
5/ 8 VDD
12 ~ 15
24 ~ 30
4/ 8 VDD
16 ~ 19
32 ~ 38
3/ 8 VDD
20 ~ 23
40 ~ 50
2/ 8 VDD
24 ~ 27
54 ~ 66
1/ 8 VDD
28 ~ 31
70 ~ ∞
R
R
R≈22kΩ
0
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
5
2000.12.31
Silan
Semiconductors SC9235
4. INITIALIZATION AND BACKUP OPERATION
1) Initialization operation
When power on, volume level is set to initial value (46dB) by setting INT pin to "L" level for a while.
VDD
VDD
INT
VIL
0V
t
t≥1ms
Adjust condenser value which is set INT pin to the period while INT pin is "L" level is longer than 1ms when
Power on.
2) Backup operation
Internal operation is all stopped when INH pin is "L" level, and prohibit input and output.
Volume data is remains while Backup mode with low current consumption.
VDD
Back up
VDD
2V
Back up data is lost
INH
0V
NORMAL MODE
VDDMIN≥2.0V
Minimum Voltage for Back up is 2.0V.
BACKUP MODE
NORMAL MODE
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
6
2000.12.31
Silan
Semiconductors SC9235
TEST CIRCUITS
VDD
A
600Ω
V-M
V
RL
1
16
2
15
3
14
4
13
SG
47μF
600Ω
RX
12
6
11
7
10
8
9
CX
RL
SG
5
V-M
V
SC9235
1/2 VDD
IDD/IQD
1/2 VDD
INH
VDD
C INT
THD —Vout
LD CHARACTERISTIC
1
fin=1kHz,Rg=600Ω
RL=100kΩ,HPF=20Hz
LPF=80kHz
10
0
VDD=6.0V
0.1
THD (%)
-10
-20
-30
0.01
-40
VDD=9.0V
-50
VDD=12.0V
0.001
0.01
0.1
1
-60
10
10
100
1000
10000
100000
fin (Hz)
Vout (Vrms)
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
7
2000.12.31
Silan
Semiconductors SC9235
TYPICAL APPLICATION CIRCUIT
Condenser for Backup
1/2 V DD
+B
1
OUT
VDD
VSS
16
2
15
OUT
3
14
IN
4
13
5
12
L- ch
R- ch
C1
IN
R
3.9kΩ
1/2 V DD
C2
UP Key
6
UP
DOWN Key
7
DN
INH
10
8
OSC
INT
9
Rx
DC-OUT
3.9kΩ
1/2 V DD
11
4.7kΩ
Cx
LEFT SIDE
RIGHT SIDE
LEVEL METER
DRIVER IC
(Note) Loudness circuit is left side, only volume (without loudness) circuit is right side.
C1=1500pF C1=0.1μF R=8.2kΩ
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
8
2000.12.31
Silan
Semiconductors SC9235
PACKAGE OUTLINE
16-DIP-P-300
UNIT:mm
7.62
6.40
0.25
2.54
1.50
15 degree
3.30
5.08
3.51
19.4
0.46
16-SOP-P-225
UNIT:mm
5.72
3.95
6.00
0.41
1.27
10.20
1.95
9.80
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
9
2000.12.31