TK15220
Audio Analog Switch
FEATURES
s
s
s
s
s
Wide Operating Voltage Range (2 to 13 V)
Low Distortion (typ. 0.004%)
Wide Dynamic Range (typ. 6 V
P-P
)
Low Output Impedance (typ. 20
Ω
)
Protection at Output Terminal.
APPLICATIONS
s
Audio Systems
s
Radio Cassettes
DESCRIPTION
The TK15220M is an Analog Switch IC that was developed
for audio frequency applications. The function of the IC is
to select one output from two input channels. The channel
selection can be controlled by a higher level by the addition
of an external resistor. The TK15220M operates from a
single power supply with the input bias built-in (V
CC
/2).
Because the distortion is very low, the TK15220M is
suitable for various signal switching applications, especially
Hi-Fi devices. The TK15220M offers a wide operating
voltage range with simple associated circuitry.
The TK15220M is available in the small SOT23L-6 plastic
surface mount package.
VCC
TK15220
IN A
VCC
GND
KEY
20 P
OUT
IN B
BLOCK DIAGRAM
VCC
IN A
+
-
VCC
OUT
VCC
KEY
ORDERING INFORMATION
IN B
+
-
GND
TK15220M
Tape/Reel Code
TAPE/REEL CODE
TL: Tape Left
June 1999 TOKO, Inc.
Page 1
TK15220
ABSOLUTE MAXIMUM RATINGS
Supply Voltage ......................................................... 14 V
Operating Voltage Range ................................. 2 to 13 V
Power Dissipation (Note 4) ................................ 200 mW
Storage Temperature Range ................... -55 to +150
°C
Operating Temperature Range ...................-20 to +75
°C
CONTROL SECTION
Input Voltage .................................... -0.3 V to V
CC
+0.3 V
ANALOG SWITCH SECTION
Signal Input Voltage ......................... -0.3 V to V
CC
+0.3 V
Signal Output Current ............................................. 3 mA
Maximum Input Frequency .................................. 100 kHz
Lead Soldering Temperature (10 s) ...................... 235
°C
TK15210M ELECTRICAL CHARACTERISTICS
Test conditions: V
CC
= 8.0 V, T
A
= 25
°C,
unless otherwise specified.
SYMBOL
I
CC
PARAMETER
Supply Current
TEST CONDITIONS
MIN
TYP
2.5
MAX
5.0
UNITS
mA
KEY CONTROL SECTION
V
IL
V
IH
I
R
Input Voltage Low Level
Input Voltage High Level
Input Resistance
Note 1
-0.3
2.0
30
+0.6
V
CC
+ 0.3
V
V
kΩ
ANALOG SWITCH SECTION
THD
N
L
CT
DYN
GVA
V
cent
∆V
cent
Z
IN
Z
OUT
Total Harmonic Distortion
Residual Noise
Cross Talk
Maximum Input Signal Level
Voltage Gain
Input-Output Terminal
Voltage
Output Terminal Voltage
Difference
Input Impedance
Output Impedance
V
IN
= 1 Vrms, f = 1 kHz
Note 2
V
IN
= 1 Vrms, f = 10 kHz,
Note 3
f = 1 kHz, THD = 0.1%
f = ~20 kHz
V
CC
/ 2 output
Between same channel
DC Impedance
DC Impedance
36
20
3.8
2.0
0
4.0
4.2
18
-80
0.004
0.008
10
-75
%
µVrms
dB
Vrms
dB
V
mV
kΩ
Ω
Note 1: The KEY input equivalent circuit is shown to the right. When the control pin
is open, the input is pulled down to a low level. This applies the channel A
input signal to the output. A high level changes the output to the channel B
input signal.
Key Input
Logic
Note 2: This value measured with a capacitor connected between the input terminal and ground. See Figure 7.
Note 3: This value measured with a 5 kΩ resistor and series capacitor connected between the input terminal and ground. See Figure 8.
Note 4: Power dissipation is 200 mW when mounted as recommended. Derate at 1.6 mW/°C for operation above 25°C.
Page 2
June 1999 TOKO, Inc.
TK15220
TEST CIRCUITS AND METHODS
VCC
SW6
10 µF
SW3
SW7
10 µF
SW8
SW9
SW2
1 kHz
1 Vrms
or
2 Vrms
10 kHz
1 Vrms
SW5
SW1
SW4
+
+
+
~
~
5 kΩ
V
~
V
_
THD
1: The above condition tests the dynamic range measurement for channel A.
2: SW5 is for residual noise measurement.
3: SW8 is for cross talk measurement.
SUPPLY CURRENT (FIGURE 1)
This current is a consumption current with a nonloading
condition.
1) Measure the inflow current to Pin 6 from V
CC
. This
current is the supply current.
VCC
+
+
~
VCC
A
OSC
V
Figure 2
KEY INPUT IMPEDANCE (FIGURE 3)
This impedance means the base resistance of the input
transistor (see terminal circuit on page 8).
1) Remove V
CC
of Pin 6.
2) Measure the resistance value by measuring instrument.
(e.g., multimeter etc.)
Figure 1
CONTROL LOW/HIGH LEVEL (FIGURE 2)
This level is to measure the threshold level.
1) Input the V
CC
to Pin 6. (This condition is the same with
the other measurements, omitted from the next for
simplicity.)
2) Input to Pin 1 with a sine wave (1 kHz, 1 Vrms).
3) Connect an oscilloscope to Pin 2.
4) Elevate the Pin 4 voltage from 0 V gradually, until the
sine wave appears at the oscilloscope. This voltage is
the threshold level when the wave appears.
June 1999 TOKO, Inc.
Figure 3
Page 3
TK15220
TEST CIRCUITS AND METHODS (CONT.)
TOTAL HARMONIC DISTORTION (FIGURE 4)
Use the lower distortion oscillator for this measurement
because the distortion of the TK15220 is very low.
1) Pin 4 is in the open condition, or high level.
2) Connect a distortion analyzer to Pin 2.
3) Input the sine wave (1 kHz, 1 Vrms) to Pin 1.
4) Measure the distortion of Pin 2. This value is the
distortion of Ach.
5) Next connect Pin 4 to the V
CC
, or high level.
6) Input the same sine wave to Pin 3.
7) Measure in the same way. This value is the distortion
of Bch.
VCC
+
VCC
+
+
~
V
~
V
~
V1
V2
Figure 5
MAXIMUM INPUT LEVEL (FIGURE 6)
This measurement measures at the output side.
1) Pin 4 is in the open condition, or low level.
2) Connect a distortion analyzer and an AC volt meter to
Pin 2.
3) Input a sine wave (1 kHz) to Pin 1 and elevate the voltage
from 0 V gradually until the distortion gets to 0.1% at Pin
2.
4) When the distortion amounts to 0.1%, stop elevating and
measure the AC level of Pin 2.
This value is the maximum input level of Ach.
5) Next, connect Pin 4 to the V
CC
, or high level.
6) Input the same sine wave to Pin 2.
7) Measure in the same way.
This value is the maximum input level of Bch.
+
~
THD
Figure 4
VOLTAGE GAIN (FIGURE 5)
This is the output level against the input level.
1) Pin 4 is in the open condition, or low level.
2) Connect AC volt meters to Pin 1 and Pin 3.
(Using the same type meter is best)
3) Input a sine wave (1 kHz) to Pin 1 (f = optional up to max.
20 kHz, 1 Vrms).
4) Measure the level of Pin 1 and name this V1.
5) Measure the level of Pin 2 and name this V2.
6) Calculate Gain = 20 Log (( |V2 - V1| )/V1)
V1<V2 = + Gain, V1>V2 = - Gain
This value is the voltage gain of Ach.
7) Next, connect Pin 4 to the GND, or high level.
8) Input the same sine wave to Pin 3.
9) Measure and calculate in the same way.
This value is the voltage gain of Bch.
VCC
+
+
~
THD
V
~
Figure 6
Page 4
June 1999 TOKO, Inc.
TK15220
TEST CIRCUITS AND METHODS (CONT.)
RESIDUAL NOISE (FIGURE 7)
This value is not a S/N ratio. This is a noise which occurs
from the device itself.
1) Pin 4 is in the open condition, or low level.
2) Connect an AC volt meter to Pin 2.
3) Connect a capacitor to GND from Pin 1.
4) Measure the AC voltage of Pin 2. This value is the noise
of Ach. If the influence of noise from outside exists, use
optional filters.
5) Next, connect Pin 4 to the V
CC
, or high level.
6) Remove the capacitor of Pin 1 and connect the capacitor
to Pin 3.
7) Measure in the same way.
This value is the noise level of Bch.
+
VCC
+
5K
+
V
~
V4
V3
V
~
~
Figure 8
I/O TERMINAL VOLTAGE (FIGURE 9)
This is the DC voltage of the input and output.
Because the input and the output are nearly equal,
only the output is measured.
1) Pin 4 is in the open condition, or low level.
2) Connect a DC volt meter to Pin 2 and measure.
This value is the terminal voltage of Ach.
3) Next, connect Pin 4 to the V
CC
, or high level.
4) Measure in the same way.
This value is the terminal voltage of Bch.
VCC
+
+
V
~
VCC
Figure 7
+
CROSS TALK (FIGURE 8)
V
This is the cross talk between Ach and Bch.
1) Pin 4 is in the open condition, or low level.
2) Connect AC volt meters to Pin 2 and Pin 3.
3) Connect a capacitor and a resistance in series to GND
from Pin 1.
4) Input a sine wave (10 kHz, 1 Vrms) to Pin 3.
5) Measure the level of Pin 3 and name this V3.
6) Measure the level of Pin 2 and name this V4.
7) Calculate:
Cross Talk = 20 Log (V4 / V3)
This value is the cross talk to Ach from Bch.
8) Next, connect Pin 4 to the V
CC
, or high level.
9) Change line of Pin 1 and Pin 3.
10) Input the same sine wave to Pin 1.
11) Measure and calculate in the same way.
This value is the isolation to Bch from Ach.
June 1999 TOKO, Inc.
Figure 9
OUTPUT TERMINAL DIFFERENCE
This is the DC output voltage difference between Ach and
Bch. This is calculated by using values measured at the
I/O Terminal Voltage.
∆
Vcent = | (Ach DC output value) - (Bch DC output
value) |
This value is the voltage difference.
Page 5