TOKO TK14588VTL

TK14588
FM IF IC
FEATURES
APPLICATIONS
■
■
■
■
■
■
■ Communications Equipment
■ Wireless LAN
■ Keyless Entry Systems
Input Frequency (~22 MHz)
Low Voltage Operation (2.3 to 5.5 V)
Battery Save Function
Wide Band Demodulator (~1 MHz)
High Speed Data Comparator (~2 Mbps)
Very Small Package (TSSOP-16)
TK14588V
DESCRIPTION
GND
RSSI
DECOUPLE
IF OUTPUT
NC
The TK14588V is a standard function general purpose IF
IC capable of operating up to 22 MHz. The TK14588V
contains a high-speed data comparator for base band
processing. The TK14588V has a unique function that
allows establishing the demodulation characteristics by
changing the external RC time constant, and not changing
the phase shifter constant. The RSSI output is individually
trimmed, resulting in excellent accuracy, good linearity,
and stable temperature characteristics. The TK14588V
was developed for high-speed data communication, DECT,
wireless LAN, keyless entry systems, etc.
DET INPUT
POWER SAVE
DET OUTPUT
VCC
AMP OUTPUT
COMP OUTPUT
COMP INPUT
COMP GND
COMP INPUT
GND
COMP INPUT
COMP INPUT
AMP OUTPUT
DET OUTPUT
DET INPUT
IF OUTPUT
RSSI
BLOCK DIAGRAM
GND
The TK14588V is available in the very small TSSOP-16
surface mount package.
IF INPUT
DECOUPLE
-
+
AMP
-
+
COMP
COMP GND
COMP OUTPUT
NC
DECOUPLE
POWER SAVE
Tape/Reel Code
DECOUPLE
IF INPUT
TK14588V
VCC
VCC
ORDERING INFORMATION
TAPE/REEL CODE
TL: Tape Left
January 2000 TOKO, Inc.
Page 1
TK14588
ABSOLUTE MAXIMUM RATINGS
Supply Voltage ........................................................... 6 V
Operating Voltage Range .............................. 2.3 to 5.5 V
Power Dissipation (Note 1) ................................ 160 mW
Storage Temperature Range ................... -55 to +150 °C
Operating Temperature Range ...................-30 to +85 °C
Operating Frequency Range (IF) ................. 6 to 22 MHz
Operating Frequecy Range (Demodulation) ..... to 1 MHz
TK14588V ELECTRICAL CHARACTERISTICS
Test conditions: VCC = 3 V, fIN = 10.7 MHz, fm = 1 kHz, Modulation = ±50 kHz, TA = 25 °C, unless otherwise specified.
SYMBOL
ICC
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
No input
3.5
5.0
mA
Power Save = ON, No input
0.2
5.0
µA
200
360
mVrms
0.5
2.0
%
Supply Current
IF
VOUT
Output Voltage
-30 dBm input
T HD
Total Harmonic Distortion
-30 dBm input
S/N
Signal to Noise Ratio
-30 dBm input
SINAD
12 dB SINAD
RIF(IN)
Limiter Input Resistance
G
Gain
120
60
70
dB
-89
-83
dBm
1.4
1.8
2.2
kΩ
69
75
No input
0.00
0.20
0.30
V
-60 dBm non-modulated input
0.40
0.55
0.70
V
-30 dBm non-modulated input
1.05
1.20
1.40
V
0 dBm non-modulated input
1.50
1.70
1.95
V
45
50
55
%
dB
RSSI
VRSSI
RSSI Output Voltage
COMPARATOR
DR
Duty Ratio
IOUT
Output Current
1
mA
Note 1: Power dissipation is 160 mW when mounted as recommended. Derate at 1.28 mW/°C for operation above 25°C.
Page 2
January 2000 TOKO, Inc.
TK14588
TEST CIRCUIT
VCC
COMP INPUT
836BH-0268 (TOKO)
DET OUTPUT
RSSI OUT
3.3 kΩ
1000 pF
0.01 µF
0.01 µF
10 kΩ
10 kΩ
12 kΩ
1 pF
51 kΩ
GND
+
-
+
AMP
COMP
VCC
VCC
0.01 µF
+
P.S.
~
50 Ω
0.01 µF
0.01 µF
3 kΩ
0.01 µF
4.7 µF
IF-INPUT
COMP
VCC
COMP
OUT
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25 °C, unless otherwise specified.
0
S+N, N, AM OUT, TOTAL
HARMONIC DISTORTION vs.
INPUT VOLTAGE
RSSI OUTPUT VOLTAGE vs.
INPUT VOLTAGE
20
2.0
VCC
5.5 V
16
-40
12
AM OUT
(30% mod.)
8
-60
-80
THD
1.6
VRSSI (V)
-20
THD (%)
S+N,N, AM OUT (dBV)
S+N
3.0 V
2.3 V
1.2
0.8
4
0.4
0
0.0
-120 -100 -80
N
-100
-120 -100 -80
-60 -40 -20
VIN (dBm)
January 2000 TOKO, Inc.
0
20
-60 -40 -20
0
20
VIN (dBm)
Page 3
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25 °C, unless otherwise specified.
DETUNE CHARACTERISTICS
S CURVE
-10
20
-30
12
-40
8
10.7
0
11.1
10.9
0
10.3
10.5
fIN (MHz)
3
VOUT
2
180
140
S/N
70
S/N (dB)
VOUT (dBV)
4
220
100
4
5
-70
-3 dB LIMITING SENSITIVITY
-80
50
1
40
0
30
2
6
-90
12 dB SINAD
3
4
-100
6
5
VCC (V)
VCC (V)
SUPPLY VOLTAGE, OUTPUT VOLTAGE,
TOTAL HARMONIC DISTORTION
vs. TEMPERATURE
5
300
SIGNAL TO NOISE RATIO,
-3 dB LIMITING SENSITIVITY,
12 dB SINAD vs. TEMPERATURE
3
VOUT
2
180
140
1
S/N
70
S/N (dB)
220
THD (%), ICC (mA)
ICC
-50
80
4
260
VOUT (mVrms)
-60
60
THD
3
11.1
SIGNAL TO NOISE RATIO,
-3 dB LIMITING SENSITIVITY,
12 dB SINAD vs. SUPPLY VOLTAGE
-50
80
THD (dB), ICC (mA)
ICC
2
10.9
fIN (MHz)
SUPPLY CURRENT, OUTPUT VOLTAGE,
TOTAL HARMONIC DISTORTION vs.
SUPPLY VOLTAGE
5
300
260
10.7
-60
60
-70
-3 dB LIMITING SENSITIVITY
-80
50
12 dB SINAD
40
-90
THD
100
-40
-20
0
20
40
TA (°C)
Page 4
-3 dB LIMITING SENSITIVITY,
12 dB SINAD (dBm)
10.5
1
4
THD
-60
10.3
2
60
80
0
100
30
-40
-20
0
20
40
60
80
-3 dB LIMITING SENSITIVITY,
12 dB SINAD (dBm)
-50
VOUT(DC) (V)
16
VOUT
THD (%)
VOUT (mVrms)
-20
3
-100
100
TA (°C)
January 2000 TOKO, Inc.
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
RSSI OUTPUT VOLTAGE vs.
TEMPERATURE
100
2.0
80
1.8
VRSSI (V)
GAIN (dB)
LIMITER GAIN vs.
INPUT FREQUENCY
60
40
VIN = 0 dBm
1.6
1.4
VIN = -15 dBm
1.2
20
1.0
-40
0
1
3
5
10
30
50
VIN = -30 dBm
-20
0
20
40
60
80
100
TA (°C)
fIN (MHz)
Data Comparator Output Voltage Transient Response
(Fall)
(Rise)
OUT
(1V/div)
IN
(10 mV/div)
OUT
(1V/div)
IN
(10 mV/div)
50 ns/div
50 ns/div
RSSI OUTPUT VOLTAGE vs.
TEMPERATURE
RSSI OUTPUT VOLTAGE vs.
INPUT VOLTAGE
2.0
1.0
VIN = -45 dBm
1.6
0.6
VRSSI (V)
VRSSI (V)
0.8
VIN = -60 dBm
0.4
VIN = -75 dBm
VIN = -90 dBm
-20
0
20
40
TA (°C)
January 2000 TOKO, Inc.
0.8
0.4
0.2
0.0
-40
1.2
60
80
100
TEMP (deg)
-30
0
25
50
70
85
0.0
-120 -100 -80 -60 -40
-20
0
20
VIN (dBm)
Page 5
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
S CURVE
3
VCC
836BH-0268 (TOKO)
VOUT(DC) (V)
RD
C
2
DET OUTPUT
1 pF
51 kΩ
RD = 1.0 k
1
RD = 2.0 k
RD = 3.3 k
0
9.9
10.3
10.7
11.1
11.5
fIN (MHz)
OUTPUT VOLTAGE vs.
MODULATING FREQUENCY
OUTPUT VOLTAGE vs.
MODULATING FREQUENCY
2
2
0 dB = 208 mVrms
RD = 3.3 kΩ
0 dB = 107 mVrms
0
RD = 2.0 kΩ
0
C=∞
C=∞
-2
C = 330 pF
VOUT (dB)
VOUT (dB)
-2
-4
C = 1000 pF
-6
C = 10 pF
-8
-10
C = 330 pF
-4
C = 1000 pF
-6
C = 10 pF
-8
-10
C = 47 pF
-12
C = 47 pF
-12
1
3
10
30
100 300
1000
MODULATING FREQUENCY fm (kHz)
1
3
10
30
100 300
1000
MODULATING FREQUENCY fm (kHz)
OUTPUT VOLTAGE vs.
MODULATING FREQUENCY
2
0 dB = 35.2 mVrms
RD = 1.0 kΩ
0
C=∞
VOUT (dB)
-2
C = 330 pF
-4
C = 1000 pF
-6
C = 10 pF
-8
-10
C = 47 pF
-12
1
3
10
30
100 300
1000
MODULATING FREQUENCY fm (kHz)
Page 6
January 2000 TOKO, Inc.
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
RSSI Output Voltage Transient Response (IF Input ON/OFF)
C
IF INPUT VOLTAGE
= -10, -40, -70 dBm
12 k
RSSI OUTPUT
C = 0.01 µF
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
SG
GATE PULSE
(1V/div)
0.1 ms/div
0.1 ms/div
C = 0.001 µF
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
SG
GATE PULSE
(1V/div)
20 µs/div
20 µs/div
C = 0.0001 µF
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
SG
GATE PULSE
(1V/div)
20 µs/div
January 2000 TOKO, Inc.
20 µs/div
Page 7
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
RSSI Output Voltage Transient Response (Power Save ON/OFF)
C
IF INPUT VOLTAGE
= -10, -40, -70 dBm
12 k
RSSI OUTPUT
C = 0.01 µF
POWER SAVE
(1V/div)
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
C = 0.001 µF
0.2 ms/div
0.2 ms/div
POWER SAVE
(1V/div)
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
20 µs/div
C = 0.0001 µF
20 µs/div
POWER SAVE
(1V/div)
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
20 µs/div
Page 8
20 µs/div
January 2000 TOKO, Inc.
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
RSSI Output Voltage Transient Response (Supply Voltage ON)
C
IF INPUT VOLTAGE
= -10, -40, -70 dBm
12 k
RSSI OUTPUT
C = 0.01 µF
VCC
(1V/div)
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
C = 0.001 µF
0.5 ms/div
VCC
(1V/div)
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
0.5 ms/div
C = 0.0001 µF
VCC
(1V/div)
RSSI OUTPUT
-10 dBm in
-40 dBm in
-70 dBm in
(0.5V/div)
0.5 ms/div
January 2000 TOKO, Inc.
Page 9
TK14588
TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)
TA = 25 °C, unless otherwise specified.
Detector Output Voltage Transient Response (Power Save ON/OFF,Supply Voltage ON)
IF INPUT VOLTAGE
= -40 dBm, No input
POWER SAVE ON/OFF
POWER SAVE
(1V/div)
DET OUTPUT
-40 dBm in,
No input
(0.5V/div)
2 ms/div
2 ms/div
SUPPLY VOLTAGE ON
VCC
(1V/div)
DET OUTPUT
-40 dBm in,
No input
(0.5V/div)
2 ms/div
Page 10
January 2000 TOKO, Inc.
TK14588
PIN FUNCTION DESCRIPTION
TERMINAL
INTERNAL EQUIVALENT CIRCUIT
PIN
NO.
1
2
3
SYMBOL
IF INPUT
DECOUPLE
DECOUPLE
DESCRIPTION
VOLTAGE
1.9 V
1.9 V
1.9 V
VCC
100 k
1: Limiting Amplifier
INPUT
2,3: Limiting Amplifier
Decoupling
1.8 k
100 k
4
NC
5
POWER SAVE
No internal connection.
However, this pin must
be connected to GND
for noise reduction.
Power Save On:
VS < 0.3 V
VS
100 k
Power Save Off:
VS = 1.5 V to VCC
100 k
6
VCC
7
8
COMP OUT
COMP GND
9
10
COMP INPUT
COMP INPUT
January 2000 TOKO, Inc.
3.0 V
0V
VCC
VCC
7: Data Comparator
Output
8: Data Comparator
GND
9,10: Data Comparator
Input
Page 11
TK14588
PIN FUNCTION DESCRIPTION
TERMINAL
INTERNAL EQUIVALENT CIRCUIT
PIN
NO.
SYMBOL
11
12
AMP OUTPUT
DET OUTPUT
DESCRIPTION
VOLTAGE
1.2 V
1.2 V
VCC
11: Amplifier Output
12: Detector Output
1.2 V
13
DET INPUT
3.0 V
Detector Input
VCC
14
IF OUTPUT
1.9 V
VCC
IF Limiter Output
100 k
15
RSSI
RSSI Output
VCC
16
GND
Page 12
0V
January 2000 TOKO, Inc.
TK14588
GND
COMP INPUT
COMP INPUT
AMP OUTPUT
DET OUTPUT
DET INPUT
IF OUTPUT
GND
RSSI
CIRCUIT DESCRIPTION
-
+
AMP
-
+
COMP
COMP GND
COMP OUTPUT
VCC
POWER SAVE
NC
DECOUPLE
IF INPUT
DECOUPLE
VCC
IF Limiter Amplifier, RSSI:
The IF limiter amplifier is composed of five differential gain stages. The total gain of the IF limiter amplifier is 80 dB. The
output signal of the IF limiter amplifier is provided at Pin 14 through the emitter-follower output stage. The IF limiter amplifier
output level is 0.5 VP-P.
The input resistance of the IF limiter amplifier is 1.8 kΩ (see Figure 1A). If the impedance of the filter is lower than 1.8
kΩ, connect an external resistor between Pin 1 and Pin 2 in parallel to provide the equivalent load impedance of the filter.
Figure 1A shows the case that the impedance of the filter is 330 Ω.
The operating current of the emitter-follower of the IF limiter amplifier output is 200 µA. If the capacitive load is heavy, the
negative half cycle of the output waveform may be distorted. This distortion can be reduced by connecting an external
resistor between Pin 14 to GND to increase the operating current. The increased operating current by an external resistor
is calculated as follows (see Figure 1B):
The increased operating current Ie (mA) = (VCC - 1.0) / Re (kΩ)
VCC
1.8 K
330
100 kΩ
200 µA
FIGURE 1A
January 2000 TOKO, Inc.
IF OUTPUT
Re
Ie
FIGURE 1B
Page 13
TK14588
CIRCUIT DESCRIPTION (CONT.)
The RSSI output is a current output. It converts to a voltage by an external resistor between Pin 15 and GND. The time
constant of the RSSI output is determined by the product of the external converting resistance and parallel capacitance.
When the time constant is longer, the RSSI output is less likely to be influenced by a disturbance or the component of
amplitude modulation, but the RSSI output response is slower. Determine the external resistance and capacitance by the
application.
VCC
OUTPUT
CURRENT
RSSI- OUT
Current-to-Voltage
Transformation Resistor
FIGURE 2 - RSSI OUTPUT STAGE
The slope of the RSSI curve characteristic can be modified by changing the external resistance. In this case, the maximum
range of converted RSSI output voltage is GND level to about VCC - 0.2 V (the supply voltage minus the collector saturation
voltage of the output transistor).
In addition, the temperature characteristic of the RSSI output voltage can be modified by changing the temperature
characteristic of the external resistor. Normally, the temperature characteristic of the RSSI output voltage is very stable
when using a carbon resistor or metal film resistor with a temperature characteristic is 0 to 200 ppm/ °C.
This product is very accurate, because the RSSI characteristic is trimmed individually.
AM Demodulation by Using the RSSI Output:
Although the distortion of the RSSI output is high because it is a logarithmic detection of the envelope to the IF input, AM
can be demodulated simply by using the RSSI output. In this case, the input dynamic range that can demodulate AM is
the inside of the linear portion of the RSSI curve characteristic (see Figure 3B).
This method does not have a feedback loop to control the gain because an AGC amplifier is not necessary (unlike the
popularly used AM demodulation method). Therefore, it is a very useful application for some uses because it does not
have the response time problem.
Figure 3A shows the AM demodulated waveform.
RSSI-OUT (V)
Operating Condition
VCC = 3 V, fIN = 10.7 MHz,
fm = 40 kHz, Mod = 80%,
VIN = 40 dBm
AM can be
demodulated
inside of linear
range
100mV/div
100µs/div
RF INPUT - LEVEL (dBu)
FIGURE 3A - AM DEMODULATED WAVEFORM
Page 14
FIGURE 3B
January 2000 TOKO, Inc.
TK14588
CIRCUIT DESCRIPTION (CONT.)
FM Detector:
The FM detector is included in the quadrature FM detector using a Gilbert multiplier.
It is suitable for high speed data communication because the demodulation bandwidth is over 1 MHz.
The phase shifter is connected between Pin 14 (IF limiter output) and Pin 13 (input detector). Any available phase shifter
can be used: a LC resonance circuit, a ceramic discriminator, a delay line, etc.
Figure 4 shows the internal equivalent circuit of the detector.
VCC
VCC
VCC
QB
QA
multiplier core circuit
FIGURE 4
The signal from the phase shifter is applied to the multiplier (in the dotted line) through emitter-follower stage QA. When
the phase shifter is connected between Pin 14 and Pin 13, note that the bias voltage to Pin 13 should be provided from
an external source because Pin 13 is only connected to the base of QA.
Because the base of QB (at the opposite side) is connected with the supply voltage, Pin 13 has to be biased with the
equivalent voltage.
Using an LC resonance circuit is not a problem (see Figure 5). However, when using a ceramic discriminator, it is necessary
to pay attention to bias. If there is a difference of the base voltages, the DC voltages of the multiplier do not balance. It
alters the DC zero point or worsens the distortion of demodulation output.
The Pin 13 input level should be saturated at the multiplier; if this level is lower, it is easy to disperse the modulation output.
Therefore, to have stable operation, Pin 13 should be higher than 100 mVP-P.
The following figures show examples of the phase shifter.
Rz is the characteristic impedance
VCC
VCC
VCC
Rz
Rz
Delay
Line
LC resonance circuit
ceramic discriminator
delay line
FIGURE 5 - EXAMPLES OF PHASE SHIFTER
January 2000 TOKO, Inc.
Page 15
TK14588
CIRCUIT DESCRIPTION (CONT.)
Establishing Demodulation Characteristics:
Generally, demodulation characteristics of FM detectors are determined by the external phase shifter. However, this
product has a unique function which can optionally establish the demodulation characteristics by the time constant of the
circuit parts after demodulation. The following explains this concept.
Figure 6 shows the internal equivalent circuit of the detector output stage.
The multiplier output current of the detector is converted to a the voltage by the internal OP AMP. The characteristic of
this stage is determined by converting the current to voltage with resistor RO and the capacitor CO connected between Pin
11 and Pin 12 (see Figure 6).
In other words, the slope of the S-curve characteristic can be established optionally with resistor RO without changing the
constant of the phase shifter. The demodulated bandwidth can be established optionally by the time constant of this
external resistor RO and capacitor CO inside of a bandwidth of the IF-filter and phase shifter. Figure 7 shows an example
of this characteristic.
The -3 dB frequency Fc is calculated by the following:
V
ref
I to V convertor
Fc =
io
R0
Demodulated
Output Current
Demodulated
Output Voltage
VOUT
C0
1
2 π C0R0
The S-curve output voltage is calculated by the following
as centering around the internal reference voltage Vref:
VOUT = Vref ± io X R0
Where Vref = 1.4 V, maximum of current io = ±100 µA
FIGURE 6 - INTERNAL EQUIVALENT CIRCUIT OF DETECTOR OUTPUT STAGE
2
0 dB = 35.2 mVrms
C=∞
0
VOUT (dB)
-2
Operating Condition:
C=
10 pF
Measured by the standard test circuit.
Parallel resistor to phase shift coil = 1 kΩ.
fIN = 10.7 MHz, modulation = ±100 kHz.
External capacitance CO = 0~1000 pF.
-4
-6
C = 330 pF
-8
C=
47 pF
C = 1000 pF
-10
-12
1
3
10
30
100 300
1000
MODULATING FREQUENCY fm (Hz)
FIGURE 7 - EXAMPLE: BANDWIDTH OF DEMODULATION VS. TIME CONSTANT CHARACTERISTIC
Center Voltage of Detector DC Output:
The center voltage of the detector DC output is determined by the internal reference voltage source. It is impossible to
change this internal reference voltage source, but it is possible to change the center voltage by the following method.
As illustrated in Figure 8, the demodulated output current at Pin 12 is converted to the voltage by an external resistor R1
without using the internal OP AMP.
Figure 9 shows an example of a simple circuit that divides the supply voltage into halves using resistors. Since both circuits
have a high output impedance, an external buffer amplifier should be connected.
Page 16
January 2000 TOKO, Inc.
TK14588
CIRCUIT DESCRIPTION (CONT.)
Vref
I to V convertor
Demodulated Output Voltage VOUT = VB ± R1 x io
Demodulated Bandwidth
Fc =
io
Demodulated
Output Current
VB
R1
C1
Demodulated
Output Voltage
VOUT
1
2 π C1(1/gm)
1/gm is about 50 kΩ that is the output resistance of the
multiplier.
Pin 11 is disconnected.
FIGURE 8 - EXAMPLE OF USING EXTERNAL REFERENCE SOURCE
Demodulated Output Voltage VOUT = VCC/2 ± R1 x io
VCC
Demodulated
Output Voltage
VOUT
R1
R2
C1
Demodulated Bandwidth
Fc =
1
2 π C1(1/gm)
1/gm is about 50 kΩ that is the output resistance of the
multiplier.
R1 = R2
Pin 11 is disconnected.
FIGURE 9 - EXAMPLE OF DIVIDING SUPPLY VOLTAGE INTO HALVES BY THE RESISTORS
Comparator:
The TK14588V contains a general purpose high-speed data comparator for the base band processing. Because the input
stage is composed of PNP transistors, it is possible to operate from a minimum voltage of 0.2 V to the supply voltage minus
0.9 V (see Figure 10).
Moreover, as the HFE of this PNP transistor is over 100, the bias current is below 0.01 µA (this is below 10% of the value
of the general products on the market using lateral PNP transistor at input stage).
INPUT STAGE
FIGURE 10 - COMPARATOR INPUT STAGE
January 2000 TOKO, Inc.
Page 17
TK14588
CIRCUIT DESCRIPTION (CONT.)
Comparator (cont.):
Figure 11 shows the internal equivalent circuit of the comparator output stage. Because the comparator output is an open
collector, it is suitable for many interface levels. This open collector output is connected with an electrostatic discharge
protection diode at the GND side only; it is not connected with it at the power supply side in consideration of operating the
voltage over the supply voltage of this IC.
When the collector pull-up resistor value is low, high operating currents result. To prevent interference to the other circuitry,
the emitter of the output transistor is brought out independently at Pin 8.
Pin 8 is not connected with the substrate and other GND internal to the IC. Therefore, when operating this comparator,
this terminal must be connected to GND.
When the comparator is operating at high speed, the etch pattern of Pins 7 and 8 (comparator output stage) should not
be run close to the etch pattern of Pin 1 (IF input). The switching waveform of the comparator output may have an effect
on the IF input and may add noise to the zero crossing of the demodulated waveform, resulting in cross over distortion.
1 mA
VCC
VCC
COMPARATOR
OUTPUT STAGE
FIGURE 11 - COMPARATOR OUTPUT STAGE
Power Save Function:
Pin 5 is the control terminal for the battery save function. The ON/OFF operation of the whole IC can be switched by
controlling the DC voltage at this terminal. Figure 12 shows the internal equivalent circuit of Pin 5.
Because it switches the bias circuit of the whole IC using the transistor in standby mode, it reduces the supply current to
near zero. As the input terminal is connected with an electrostatic discharge protection diode at GND side only, it is possible
to control the voltage above the supply voltage. It is possible to go into standby mode by disconnecting Pin 5, but it is not
recommended because Pin 5 is a high impedance and may malfunction by an external disturbance.
When Pin 5 is disconnected, a suitable capacitor should be connected between Pin 5 and GND.
VCC
BIAS
50 K
Vs
FIGURE 12
Page 18
January 2000 TOKO, Inc.
TK14588
TEST BOARD
C1 = C2 = C4 = C6 = C8 = C9 = C10 = 0.01 µF
C3 = 4.7 µF, C5 = 1000 pF, C7 = 1 pF
R1 = 51 Ω, R2 = 51 kΩ, R3 = 3.3 kΩ, R4 = 12 kΩ, R5 = 3 kΩ
L1 = L2 = 10 µH
L3 = 836BH-0268 (TOKO)
January 2000 TOKO, Inc.
Page 19
TK14588
PACKAGE OUTLINE
Marking Information
TSSOP-16
TK14588V
14588
1.0
0.35
4.8
Marking
4.4
AAAAA
YYY
e 0.65
Recommended Mount Pad
1
+0.15
-0.15
0.9
0.50
+0.15
-0.15
e 0.65
0.15
0 ~ 0.15
0.25
1.2 max
5.0
0 ~ 10
Lot. No.
0.1
6.4
0.12
+ 0.3
M
Dimensions are shown in millimeters
Tolerance: x.x = ± 0.2 mm (unless otherwise specified)
Toko America, Inc. Headquarters
1250 Feehanville Drive, Mount Prospect, Illinois 60056
Tel: (847) 297-0070
Fax: (847) 699-7864
TOKO AMERICA REGIONAL OFFICES
Midwest Regional Office
Toko America, Inc.
1250 Feehanville Drive
Mount Prospect, IL 60056
Tel: (847) 297-0070
Fax: (847) 699-7864
Western Regional Office
Toko America, Inc.
2480 North First Street , Suite 260
San Jose, CA 95131
Tel: (408) 432-8281
Fax: (408) 943-9790
Eastern Regional Office
Toko America, Inc.
107 Mill Plain Road
Danbury, CT 06811
Tel: (203) 748-6871
Fax: (203) 797-1223
Semiconductor Technical Support
Toko Design Center
4755 Forge Road
Colorado Springs, CO 80907
Tel: (719) 528-2200
Fax: (719) 528-2375
Visit our Internet site at http://www.tokoam.com
The information furnished by TOKO, Inc. is believed to be accurate and reliable. However, TOKO reserves the right to make changes or improvements in the design, specification or manufacture of its
products without further notice. TOKO does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of
third parties which may result from the use of its products. No license is granted by implication or otherwise under any patent or patent rights of TOKO, Inc.
Page 20
© 1999 Toko, Inc.
All Rights Reserved
January 2000 TOKO, Inc.
IC-119-TK119xx
0798O0.0K
Printed in the USA