Overview
The STK301-220 is a hybrid IC (HIC) for electronically
controlled graphic equalizer applications and is equipped
with on-chip electronic volume control for 7-band, 2-
channel graphic equalization, thereby permitting one-
touch up-down control of all band gains. The STK301-
220 is a hybrid IC which combines SC system and
photoresist techniques with folded board construction
while incorporating Sanyo's unique insulated metal
substrate technology (IMST) to the base.
Applications
Car stereos
Portable radio-cassette players
Home stereos
Features
All bands are set for L/R simultaneous 2 dB incremental
operation (typ).
All bands are equipped with 13 positions and range
between +12 dB maximum boost to 12 dB maximum cut.
Crossover frequencies include fo; 60 Hz, 150 Hz,
400 Hz, 1 kHz, 2.5 kHz, 6 kHz and 15 kHz.
The following features can be made available with an
electronic graphic equalizer system which incorporates
the 3-IC construction consisting of the STK301-220, a
controller (universal microcontroller) along with the
display LSI (LC75821
LCD, LC7565
FLT, LED):
-- One-touch up-down control of all band gains.
-- Immediate recall of preferred frequency levels tailored
to suit musical selections. This is possible using preset
functions to retrieving items from one-touch memory.
-- Such functions as setting all bands to 0 dB (flat
function), or switching frequency characteristics
from 0 dB to center (reverse function) may be
simply performed with supported software.
-- Dual control lines permit mutual use with display
LSI and help to simplify wiring between
microcontroller and LSI.
Minimal operating shock noise when boost or cut is used.
Package Dimensions
unit : mm
4143
Thick-Film Hybrid IC
N3096HA (OT)/82294TH (OT) 5-3398 No. 4793-1/8
[STK301-220]
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
7-band, 2-channel Electronic Graphic Equalizer
STK301-220
Ordering number : EN4793A
Specifications
Maximum Ratings
at Ta = 25C, V
SS
= 0 V
Parameter
Symbol
Conditions
Ratings
Unit
V
DD
-V
EE
max
16
V
Maximum supply voltage
V
CC
1 max
18 (36)
V
V
CC
2 max
7
V
Input voltage
V
I
1
CLK, DI, IN1, IN2
0 to V
CC
2 + 0.3
V
V
I
2
CLK, DI, IN1, IN2
V
EE
0.3 to V
DD
+ 0.3
V
Allowable power dissipation
Pd max
920
mW
Operating temperature
Topr
20 to +70
C
Storage temperature
Tstg
40 to +100
C
No. 4793-2/8
STK301-220
Recommended Operational Voltage
at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Unit
V
DD
/V
EE
V
SS
= 0 V
7 (14)
V
Supply voltage
V
CC
1
V
SS
= 0 V
7 (14)
V
V
CC
2
V
SS
= 0 V
5
V
Allowable Operating Ranges
at Ta = 25C, V
SS
= 0 V
Parameter
Symbol
Conditions
Ratings
Unit
V
DD
-V
EE
7.5 to 15.0
V
Supply voltage
V
CC
1
4 to 18 (8 to 36)
V
V
CC
2
4.5 to 5.5
V
Input high level voltage
V
IH
CLK, DI
0.8 V
CC
2 to V
CC
2
V
Input low level voltage
V
IL
CLK, DI
0.2 V
CC
2
V
Input pulse width
t
W
CLK
from 1
s
Setup time
t
setup
DI
from 1
s
Hold time
t
hold
DI
from 1
s
Operating frequency
f
opg
CLK
up to 330
kHz
Operating Characteristics
at Ta = 25C, V
SS
= 0 V, V
DD
/V
EE
= 7 V, V
CC
1 = 7 V, V
CC
2 = 5 V, f = 1 kHz
All bands flat, using the specified test circuit
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
I
DD
V
DD
/V
EE
= 7 V, V
CC
1 = 7 V,V
SS
= 0 V
1
mA
Current dissipation
I
CC
1
V
CC
2 = 5 V
20
30
mA
I
CC
2
1
mA
Voltage gain
VG
V
IN
= 10 dB4.0
1.0
+2.0
dB
Total harmonic distortion
THD
f = 1 kHz, V
O
= 1V, 30 kHz L.P.F
0.005
0.1
%
Crosstalk
C.T.
f = 20 kHz, V
IN
= 0 dB
45
55
dB
Output noise voltage
V
NO
Rg = 0
, 10 Hz to 30 kHz B.P.F
9
25
V
Setting error
B
1
+1
dB
f (1)
f = 60 Hz
10
12
14
dB
f (2)
f = 150 Hz
10
12
14
dB
f (3)
f = 400 Hz
When operating at f = 1 kHz,
10
12
14
dB
Frequency response
f (4)
f = 1 kHz
all bands are flat and
10
12
14
dB
f (5)
f = 2.5 kHz V
O
= 10 dB set at 0 dB.
10
12
14
dB
f (6)
f = 6 kHz
10
12
14
dB
f (7)
f = 15 kHz
10
12
14
dB
Note: With constant voltage power supply.
The supply voltage figures in parentheses indicate the voltages when a single voltage power supply is used.
Internal Equivalent Circuit
Sample Application Circuit
Single Power Supply
Split Power Supply
Unit (resistance:
, capacitance:F)
Unit (resistance:
, capacitance:F)
No. 4793-3/8
STK301-220
No. 4793-4/8
STK301-220
Pin Descriptions
Pin No.
Pin name
Functions
1
+V
CC
1
Power supply pin used for + power supply to IC2 and IC3 graphic equalizer.
2, 21
DC
Pin for 1/2 V
CC
1 decoupling capacitor of graphic equalizer IC. When shortened, power supply becomes more effective and
ripples are vulnerable.
3
OUTPUT 1
Output pin 1.
4
NF 1
Inverting input for the graphic equalizer IC2 internal operational amplifier.
5
1IN 1
Audio signal input 1 (INPUT1) for electronic volume control IC1
6
INPUT 1
Input impedance for input pin 1 rated at approximately 60 k
(1 kHz, flat).
7
1IN 2
Audio signal input 2 (INPUT1) for electronic volume control IC1
8
V
SS
Power supply pin connected to ground (GND).
9
V
EE
Power supply pin used for audio signal power supply to electronic volume control section. When single power supply is used,
connect to V
SS
.
10
CLK
Input pin for data from CPU according to Schmitt inverter format.
11
DI
Input pin for clock from the CPU according to Schmitt inverter format.
12
+V
CC
2
Power supply pin rated at +5 V (typ). Make sure that V
CC
2 does not onset before V
DD
.
13
GND (V
CC
1)
Power supply pin for ground (- power supply) of IC2 and IC3 graphic equalizer.
14
V
DD
Power supply pin used for audio signal power supply to electronic volume control section.
Select pin for applications using two ICs. Input "1" to initiate key code 7C3 for
15
S
connecting to V
DD
. Input "0" to initiate key code 7C2 for connecting to V
EE
.
16
2IN 2
Audio signal input 2 (INPUT2) for electronic volume control IC1
17
INPUT 2
Input impedance for input pin 2 rated at approximately 60 k
(1 kHz, flat).
18
2IN 1
Audio signal input 1 (INPUT2) for electronic volume control IC1
19
NF 2
Inverting input for the graphic equalizer IC3 internal operational amplifier.
20
OUTPUT 2
Output pin 2.
Note: Refer to LC7522 or LC7523 specifications concerning pins which do not appear here and are hybrid IC (HIC) pins connected directly to a LC7522 or
LC7523 pins.
Description of Operation
The STK301-220 is a hybrid IC (HIC) with a 7-component 2-channel construction for electronically controlled graphic
equalizer applications. It employs an LC7522 for graphic equalizer electronic volume control and an M5229 for 7-
component graphic equalizer functions.
Figure 1 Equivalent Circuit Block Diagram
Pins f (1) through f (7) are used as pin connections for the
LC7522 band filter. Supported frequencies and their pin
assignments are listed in the following.
Pin Name
Frequency
f (1)
60Hz
f (2)
150Hz
f (3)
400Hz
f (4)
1kHz
f (5)
2.5kHz
f (6)
6kHz
f (7)
15kHz
In order to minimize the noise which occurs during changeover,
connections are made using 1 M
resistors from pins f (1)
through f (7) to 1/2 V
CC
1.
Resistor Equivalent Circuit
(single band)
Principles of Operation
The graphic equalizer section is constructed from 7 resonance circuits and output buffer amplifiers (every channel);
variable resistors (LC7522) and resonance circuit capacitors C1 and C2 are built-in. Resonance circuits utilize
semiconductor inductors and apply resonation to reduced impedance; all frequency gains are altered.
1. Resonance Circuit
Semiconductor inductors replace the L of the R, L, C series
resonance circuit with a CR element passing through the
buffer function of active elements such as the transistor and
op-amp (operational amplifier), thereby effecting the
equivalent operation of a R, L, C series resonance circuit.
The STK301-220 resonance circuit buffer is constructed
using transistors and arranged as illustrated in Figure 2.
Resonance frequency fo is determined using the following
formula:
fo =
Figure 2 Resonance Circuit
2. Flat, Boost and Cut
Gains matching resonance circuit frequency gains are altered
by altering the built-in resonance circuits and electronic
volume control. Figure 3 is presented to describe the
equivalent circuit. Z represents the impedance of the
resonance circuit in Figure 2.
Figure 3 Equivalent Circuit
No. 4793-5/8
STK301-220
2
1
C1 C2 R1 R2
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