LINER LTC1565-31CS8 650khz continuous time, linear phase lowpass filter Datasheet

LTC1565-31
650kHz Continuous Time,
Linear Phase Lowpass Filter
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FEATURES
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DESCRIPTIO
7th Order, 650kHz Linear Phase Filter in an SO-8
Differential Inputs and Outputs
Operates on a Single 5V or a ±5V Supply
Low Offset: 5mV Typical
75dB THD and SNR
78dB SNR
Shutdown Mode
Requires No External Components
Requires No External Clock Signal
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APPLICATIO S
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CDMA Base Stations
Data Communications
Antialiasing Filters
Smoothing or Reconstruction Filters
Matched Filter Pairs
Replacement for LC Filters
The LTC®1565-31 is a 7th order, continuous time, linear
phase lowpass filter. The selectivity of the LTC1565-31,
combined with its linear phase and dynamic range, make it
suitable for filtering in data communications or data acquisition systems. The filter attenuation is 36dB at 2× fCUTOFF
and at least 72dB for frequencies above 3× fCUTOFF. Unlike
comparable LC filters, the LTC1565-31 achieves this selectivity with a linear phase response in the passband.
With 5% accuracy of the cutoff frequency, the LTC1565-31
can be used in applications requiring pairs of matched filters,
such as transceiver I and Q channels. Furthermore, the
differential inputs and outputs provide a simple interface for
these wireless systems.
With a single 5V supply and a 2VP-P input, the LTC1565-31
features an impressive spurious free dynamic range of 75dB.
The maximum signal-to-noise ratio is 78dB and it is achieved
with a 2.5VP-P input signal.
The LTC1565-31 features a shutdown mode where power
supply current is typically less than 10µA.
For W-CDMA, 3G, CDMA 2000 and other cellular and
noncellular cutoff frequencies or single-ended I/O, please
contact LTC Marketing for additional information.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
Frequency Response
2.0
10
0
Single 5V Supply, Differential 650kHz Lowpass Filter
2
–IN
+OUT
–OUT
7
VOUT+
VOUT–
LTC1565-31
3
0.1µF
4
GND
V–
V
5V
+
SHDN
6
5V
0.1µF
5
15645-31 TA01
GAIN (dB)
VIN–
+IN
8
1.9
–10
1.8
–20
1.7
–30
1.6
–40
1.5
DELAY
–50
1.4
–60
1.3
–70
1.2
–80
1.1
–90
1.0
–100
104
105
106
FREQUENCY (Hz)
DELAY (µs)
VIN+
1
GAIN
0.9
107
1565 G01
1
LTC1565-31
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ABSOLUTE MAXIMUM RATINGS
PACKAGE/ORDER INFORMATION
(Note 1)
Total Supply Voltage ............................................... 11V
Power Dissipation ............................................. 500mW
Operating Temperature Range
LTC1565-31CS8 ..................................... 0°C to 70°C
LTC1565-31IS8 ................................. – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
TOP VIEW
+IN 1
8
+OUT
–IN 2
7
–OUT
GND 3
6
V+
5
SHDN
V–
4
LTC1565-31CS8
LTC1565-31IS8
S8 PART MARKING
S8 PACKAGE
8-LEAD PLASTIC SO
156531
56531I
TJMAX = 150°C, θJA = 80°C/ W (NOTE 4)
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = 5V, RLOAD = 10k from each output to AC ground, and Pin 5 open
unless otherwise specified.
PARAMETER
CONDITIONS
MIN
Operating Supply Voltage
TYP
4.75
Filter Gain
VIN = 1VP-P, fIN = 25kHz
fIN = 200kHz (Gain Relative to 25kHz)
fIN = 300kHz (Gain Relative to 25kHz)
fIN = 500kHz (Gain Relative to 25kHz)
fIN = 650kHz (Gain Relative to 25kHz)
fIN = 900kHz (Gain Relative to 25kHz)
fIN = 1.3MHz (Gain Relative to 25kHz)
fIN = 2.3MHz (Gain Relative to 25kHz)
Filter Phase
VIN = 1VP-P, fIN = 25kHz
fIN = 200kHz
fIN = 300kHz
fIN = 500kHz
fIN = 600kHz
fIN = 650kHz
fIN = 900kHz
●
●
●
●
●
●
●
– 0.3
– 0.2
– 0.7
– 2.2
–4
●
– 162
●
34
●
1.95
0
0
–0.4
–1.6
–3
–11
–36
–72
–13
–101
–150
113
60
36
– 92
UNITS
11
V
0.3
0.1
– 0.1
– 0.95
–2
–7
– 31
dB
dB
dB
dB
dB
dB
dB
dB
– 138
85
Deg
Deg
Deg
Deg
Deg
Deg
Deg
Phase Linearity
Ratio of 600kHz Phase/300kHz Phase
Wideband Noise
Noise BW = DC to 2 • fCUTOFF
118
µVRMS
THD
fIN = 100kHz, 1VP-P (Note 2)
86
dB
Filter Differential DC Swing
Maximum Difference Between Pins 7 and 8
VS = 5V
VS = ±5V
Input Bias Current
2
2.03
±1.7
±2.3
±1.9
±2.5
VP
VP
0.3
0.6
µA
±10
nA
Common Mode, VIN = 2.5V
Differential
75
145
MΩ
MΩ
VS = 5V
VS = ±5V (Note 5)
±5
±5
Input Capacitance
Output DC Offset (Note 3)
±1.4
±2.2
0.1
Input Offset Current
Input Resistance
●
●
2
MAX
3
pF
±12
±12
mV
mV
LTC1565-31
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = 5V, RLOAD = 10k from each output to AC ground, and Pin 5 open
unless otherwise specified.
PARAMETER
CONDITIONS
Output DC Offset Drift
VS = 5V
VS = ±5V
MIN
Ground Voltage (Pin 3) in
Single Supply Applications
VS = 5V
●
2.49
SHDN Pin Logic Thresholds
VS = 5V, Minimum Logical “1”
VS = 5V, Maximum Logical “0”
●
●
3.3
VS = ±5V, Minimum Logical “1”
VS = ±5V, Maximum Logical “0”
●
●
2.4
TYP
MAX
UNITS
µV/°C
µV/°C
– 400
– 400
2.51
2.52
V
4.2
V
V
2.9
V
V
µA
µA
SHDN Pin Pull-Up Current
VS = 5V
VS = ±5V
5
9
Power Supply Current
VS = 5V
VS = ±5V
●
●
24
25
31
33
mA
mA
Power Supply Current in Shutdown Mode
Shutdown. Includes SHDN Pull-Up Current
VS = 5V
VS = ±5V
●
●
8
20
16
40
µA
µA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Input and output voltages expressed as peak-to-peak numbers are
assumed to be fully differential.
Note 3: Output DC offset is measured between Pin 8 and Pin 7 with Pin 1
and Pin 2 connected to Pin 3.
Note 4: Thermal resistance varies depending upon the amount of PC board
metal attached to the device. θJA is specified for a 3.8 square inch test
board covered with 2 oz copper on both sides.
Note 5: Output DC offset measurements are performed by automatic test
equipment approximately 0.5 seconds after application of power.
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TYPICAL PERFOR A CE CHARACTERISTICS
Passband Gain and Delay
vs Frequency
Frequency Response
GAIN
2.0
0.5
1.9
0
1.8
–20
1.7
–30
1.6
–40
1.5
DELAY
–50
1.4
–60
1.3
2.0
GAIN
5V
–0.5
1.9
±5V
1.8
–1.0
1.7
–1.5
1.6
–2.0
1.5
DELAY
–2.5
1.4
1.2
–3.0
1.3
–80
1.1
–3.5
1.2
–90
1.0
–4.0
1.1
–70
–100
104
105
106
FREQUENCY (Hz)
0.9
107
1565 G01
TA = 25°C
–4.5
25k
100k
FREQUENCY (Hz)
DELAY (µs)
–10
DELAY (µs)
GAIN (dB)
0
GAIN (dB)
10
1.0
1M
1565 G02
3
LTC1565-31
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TYPICAL PERFOR A CE CHARACTERISTICS
Passband Gain vs Frequency
Over Temperature
0.5
VS = 5V
0.4
0.3
–40
–40
–50
–50
–60
–60
VS = 5V
85°C
0
25°C
–0.1
–70
VS = 5V
–80
VS = ±5V
GAIN (dB)
–40°C
0.1
GAIN (dB)
GAIN (dB)
0.2
Stopband Gain vs Frequency
Over Temperature
Stopband Gain vs Frequency
–40°C
25°C
85°C
–70
–0.2
–0.3
–80
–0.4
–0.5
25k
100k
FREQUENCY (Hz)
–90
1.5
400k
1.8
2.4
2.1
FREQUENCY (MHz)
2.7
1565 G03
Common Mode Rejection Ratio
2.7
3.0
70
Supply Current vs Temperature
26
VIN = 200mVP-P
VS = 5V
TA = 25°C
SUPPLY CURRENT (mA)
VIN = 1VP-P
VS = 5V
100 TA = 25°C
PSRR (dB)
90
CMRR (dB)
2.4
2.1
FREQUENCY (MHz)
1565 G04
Power Supply Rejection Ratio
80
80
1.8
1565 G04
110
60
50
70
25
VS = ±5V
VS = 5V
24
40
60
50
103
–90
1.5
3.0
104
105
106
FREQUENCY (Hz)
107
30
103
104
105
106
FREQUENCY (Hz)
1565 G06
107
1565 G07
23
–50 –30
30
50
–10 10
TEMPERATURE (°C)
70
90
1565 G08
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PIN FUNCTIONS
+IN, –IN (Pins 1, 2): Input Pins. Signals can be applied to
either or both input pins. The typical DC gain from differential inputs (Pin 1 to Pin 2) to the differential outputs (Pin
8 to Pin 7) is 1.0V/V. The input range is described in the
Applications Information section.
GND (Pin 3): Ground. The ground pin is the reference
voltage for the filter and is internally biased to one-half the
total power supply voltage of the filter, maximizing the
dynamic range of the filter. For single supply operation,
the ground pin should be bypassed with a quality 0.1µF
4
ceramic capacitor to Pin 4. For dual supply operation,
connect Pin 3 to a high quality DC ground. A ground plane
should be used. A poor ground will increase noise and
distortion.
The impedance seen at Pin 3 is 2.5kΩ in normal mode. In
shutdown, the pin is internally biased to the same levels
as normal mode. The impedance in shutdown mode is
typically 500kΩ but varies with supply voltage and
temperature.
LTC1565-31
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PIN FUNCTIONS
V –, V + (Pins 4, 6): Power Supply Pins. For a single 5V
supply (Pin 4 grounded), a quality 0.1µF ceramic bypass
capacitor is required from the positive supply pin (Pin 6)
to the negative supply pin (Pin 4). The bypass should be
as close as possible to the IC. For dual supply applications
(Pin 3 is grounded), bypass Pin 6 to Pin 3 and Pin 4 to Pin
3 with a quality 0.1µF ceramic capacitor.
The maximum voltage difference between the ground pin
(Pin 3) and the positive supply pin (Pin 6) should not
exceed 5.5V.
SHDN (Pin 5): Shutdown. When the Pin 5 voltage is low,
the LTC1565-31 goes into the current saving shutdown
mode. Pin 5 has a 4µA pull-up current. Leaving Pin 5 open
will place the LTC1565-31 in its normal operating mode.
– OUT, + OUT (Pins 7, 8): Output Pins. Pins 7 and 8 are the
filter differential output. Each pin can drive 1kΩ or 300pF
loads. The common mode voltage at the output pins is the
same as the voltage at Pin 3.
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BLOCK DIAGRA
+IN 1
+
8 +OUT
–
R
+
R
–
–
7th ORDER
LINEAR
PHASE
FILTER
NETWORK
OUTPUT
BUFFER
OUTPUT
BUFFER
7 –OUT
–IN 2
+
INPUT BUFFERS
WITH COMMON MODE
TRANSLATION CIRCUIT
V+
~1M
SHUTDOWN
SWITCH
5k
6 V+
GND 3
5k
~1M
SHUTDOWN
SWITCH
V+
V–
V– 4
4µA
SHUTDOWN
5
SHDN
1565-31 BD
5
LTC1565-31
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APPLICATIONS INFORMATION
Interfacing to the LTC1565-31
Input Common Mode and Differential Voltage Range
The difference between the voltages at Pin 1 and Pin 2 is
the “differential input voltage.” The average of the voltages
at Pin 1 and Pin 2 is the “common mode input voltage.”
The difference between the voltages at Pin 7 and Pin 8 is
the “differential output voltage.” The average of the voltages at Pin 7 and Pin 8 is the “common mode output
voltage.” The input and output common mode voltages
are independent. The input common mode voltage is set
by the signal source, if DC coupled, or by the biasing
network if AC coupled (Figures 1 and 2). The output
common mode voltage is equal to the voltage of Pin 3, the
GND pin. The GND pin is biased to one-half of the supply
voltage by an internal resistive divider (see Block Diagram). To alter the common mode output voltage, Pin 3
can be driven with an external voltage source or resistor
network. If external resistors are used, it is important to
note that the internal 5k resistors can vary ±20% (their
ratio only varies ±1%). The output can also be AC coupled.
The range of voltage each input can support while operating in its linear region is typically 0.8V to 3.7V for a single
5V supply and – 4.2V to 3.2V for a ±5V supply. Therefore,
the filter can accept a variety of common mode input
voltages. Figures 3 and 4 show the THD of the filter versus
common mode input voltage with a 2VP-P differential input
signal.
1
2
+
–
VIN+
+
–
+IN
–IN
VIN–
–OUT
4
V–
VS = ±5V
THD (dB)
–50
–70
–80
–90
VOUT+
7
VOUT–
SHDN
6
–30
0.1µF
5
THD (dB)
Figure 1
–60
–80
1
2
+IN
+OUT
–IN
–OUT
100k
1µF
8
VOUT+
7
VOUT–
5V
LTC1565-31
3
4
GND
V–
V
+
SHDN
5
AC COUPLED INPUT
VIN (COMMON MODE) = VOUT (COMMON MODE)
=
Figure 2
V+
2
VIN = 2VP-P
fIN = 100kHz
0.5
3.0
1.0
2.0
2.5
1.5
INPUT COMMON MODE VOLTAGE (V)
3.5
1565-31 F04
Figure 4. THD vs Common Mode Input Voltage
6
0.1µF
15645-31 F02
6
–50
–70
0.1µF
VIN– 0.1µF 100k
VS = 5V
–40
V + + VIN–
VIN (COMMON MODE) = IN
2
V + + VOUT– V+
=
VOUT (COMMON MODE) = OUT
2
2
+
–
5
Figure 3. THD vs Common Mode Input Voltage
DC COUPLED INPUT
VIN+
VIN = 2VP-P
fIN = 100kHz
1565-31 F03
15645-31 F01
+
–
–60
5V
V+
GND
–40
–5 –4 –3 –2 –1 0 1 2 3 4
INPUT COMMON MODE VOLTAGE (V)
8
LTC1565-31
3
0.1µF
+OUT
–30
Figure 5 shows the THD and S/N ratio versus differential
input voltage level for both a single 5V supply and a ±5V
supply. The common mode voltage of the input signal is
one-half the total power supply voltage of the filter. The
spurious free dynamic range, where the THD and S/N ratio
are equal, is 75dB to 76dB when the differential input
voltage level is 2VP-P; that is, for a single 5V supply, the
LTC1565-31
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APPLICATIONS INFORMATION
–40
THD, SNR (dB)
Output Common Mode and Differential Voltage Range
THD: VS = 5V, VCM = 2.5V
THD: VS = ±5V, VCM = 0V
SNR
fIN = 100kHz
The output is a fully differential signal with a common mode
level equal to the voltage at Pin 3. The specifications in the
Electrical Characteristics table assume the inputs are driven
differentially and the output is observed differentially.
However, Pin 8 can be used as a single-ended output by
simply floating Pin 7. Pin 7 can be used as an inverting
single-ended output by floating Pin 8. Using Pins 7 or 8 as
single-ended outputs will decrease the performance.
–50
–60
–70
–80
–90
0.5
1.0
3.0
1.5
2.0
2.5
DIFFERENTIAL INPUT (P-P)
3.5
1565-31 F05
Figure 5. Dynamic Range Diff-In, Diff-Out
input voltages are Pin 1 = 2.5V DC ±0.5V and Pin 2 = 2.5V
DC ±0.5V. Also note Figure 5 shows a 78dB SNR ratio for
higher THD levels.
As seen in Figures 3 and 4, the spurious free dynamic
range can be optimized by setting the input common mode
voltage slightly below one-half of the power supply voltage, i.e., 2V for a single 5V supply and – 0.5V for a ±5V
supply. Figure 6 shows the THD and SNR ratio versus
differential input voltage level for both a single 5V supply
and a ±5V supply when the common mode input voltage
is 2V and – 0.5V respectively.
The common mode output voltage can be adjusted by
overdriving the voltage present on Pin 3. The best performance is achieved using a common mode output voltage
that is equal to mid supply (the default Pin 3 voltage). Figures 7 and 8 illustrate the THD versus output common mode
voltage for a 2VP-P differential input voltage and a common
mode input voltage that is 0.5V below mid supply.
0
–20
–40
–60
–70
–80
1.0
2.0
2.5
3.5
4.0
1.5
3.0
COMMON MODE OUTPUT VOLTAGE (V)
1565-31 F07
Figure 7. THD vs Common Mode Output Voltage
THD: VS = 5V, VCM = 2V
THD: VS = ±5V, VCM = –0.5V
SNR
fIN = 100kHz
0
VIN = 2VP-P 100kHz
–10 VS = ±5V
VIN(CM) = –0.5V
–20
–50
–30
–60
THD (dB)
THD, SNR (dB)
–40
–30
–50
For best performance, the inputs should be driven differentially. For single-ended signals, connect the unused
input to Pin 3 or a common mode reference.
–30
VIN = 2VP-P 100kHz
VS = 5V
VIN(CM) = 2V
–10
THD (dB)
–30
–70
–40
–50
–60
–80
–70
–90
0.5
1.5
2.0
2.5
3.0
1.0
DIFFERENTIAL INPUT VOLTAGE (VP-P)
3.5
1565-31 F06
Figure 6. THD vs VIN for a Common Mode
Input Voltage 0.5V Below Mid Supply
–80
–90
–4
0
1
2
–3 –2 –1
3
COMMON MODE OUTPUT VOLTAGE (V)
4
1565-31 F08
Figure 8. THD vs Common Mode Output Voltage
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LTC1565-31
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APPLICATIONS INFORMATION
Output Drive
concentrated in the filter passband and cannot be removed
with post filtering (Table 1). Table 2 lists the typical change
in wideband noise with supply voltage.
Pin 7 and Pin 8 can drive a 1kΩ or 300pF load connected
to AC ground with a ±0.5V signal (corresponding to a
2VP-P differential signal). For differential loads (loads
connected from Pin 7 to Pin 8) the outputs can produce
a 2VP-P differential signal across 2kΩ or 150pF. For
smaller signal amplitudes the outputs can drive correspondingly larger loads.
Table 1. Wideband Noise vs Bandwidth, Single 5V Supply
BANDWIDTH
TOTAL INTEGRATED NOISE
DC to fCUTOFF
104µVRMS
DC to 2 • fCUTOFF
118µVRMS
Table 2. Wideband Noise vs Supply Voltage, fCUTOFF = 650kHz
Noise
The wideband noise of the filter is the RMS value of the
device’s output noise spectral density. The wideband
noise data is used to determine the operating signal-tonoise at a given distortion level. Most of the noise is
POWER SUPPLY
TOTAL INTEGRATED NOISE
DC TO 2 • fCUTOFF
5V
118µVRMS
±5V
120µVRMS
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TYPICAL APPLICATIO S
Test Circuit for Single 5V Supply Operation
4.99k
AMPLIFIERS A1, A2 AND A3 ALLOW THE USE OF A GROUNDREFERENCED SINGLE-ENDED AC SOURCE AS THE INPUT
SIGNAL AND A SEPARATE GROUND-REFERENCED DC SOURCE
TO PROVIDE THE INPUT DC COMMON MODE VOLTAGE
AMPLIFIERS A4 AND A5 ALLOW MONITORING/MEASURING
THE DIFFERENTIAL OUTPUT WITH A SINGLE-ENDED, GROUNDREFERENCED INSTRUMENT
5V
4.99k
2.49k
2
3
–
0.1µF
7
A1
LT®1809
6
+
4
10µF
2.49k
4.99k
5V
4.99k
VIN
2
–
+
–
3
0.1µF
7
+VIN/2 + VCM 1
6
A2
VCM 2.49k
5V
+LT1809
–VIN/2 + VCM 2
4
4.99k
+IN
–IN
10µF
+OUT
–OUT
8
4.99k
7
2.49k
GND
V+
+
6
V–
SHDN
A4
LT1809
6
VOUT
(SINGLE ENDED)
5V
1k
0.1µF
4
0.1µF
7
4
0.1µF
4.99k
3
–
2.49k
LTC1565-31
3
2
5
5V
0.01µF
19k
5V
2
4.99k
2
–
3
6
+LT1809
4
8
0.1µF
7
A3
2.49k
–
V +/2
1k
3
+
0.1µF
7
A5
LT1812
6
20Ω
2.2µF
4
0.1µF
1565-31 TA08
LTC1565-31
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TYPICAL APPLICATIO S
Single-Ended Input/Output Dual Supply Filter
4.99k
5V
VIN
1
2
+OUT
+IN
–OUT
–IN
8
4.99k
2
–
7
2.49k
3
+
0.1µF
7
6
LT1809
4
LTC1565-31
3
V+
GND
6
5V
0.1µF
–5V
R2
2.49k
0.1µF
4
V–
SHDN
VOUT
0.1µF
–5V
5
1565-31 TA09
0.1µF
NOTE: FOR SINGLE 5V SUPPLY CONNECTION, PIN 4 (LTC1565-31)
AND PIN 4 (LT1809) SHOULD BE GROUNDED AND RESISTOR
R2 SHOULD BE DC BIASED AT APPROXIMATELY 2.5V
(SEE TEST CIRCUIT FOR SINGLE SUPPLY OPERATION)
A Fully Differential Filter with Adjustable Output Common Mode Voltage
VIN+*
1
VIN–*
2
+IN
+OUT
–IN
–OUT
8
VOUT+
7
VOUT–
VOUT(CM) = V – +
(V + – V –)R2
R1 + R2
LTC1565-31
3
GND
V+
6
5V
0.1µF
4
–5V
V–
SHDN
5
0.1µF
–3V ≤ VOUT(CM) ≤ 3V
5V
V+
2
–
3
+
R1
7
LT1812
*–3.4V ≤ VIN(CM) ≤ 2.5V
VIN(CM) CAN BE EQUAL OR
DIFFERENT FROM VOUT(CM)
0.1µF
NOTE: FOR SINGLE 5V SUPPLY OPERATION,
PIN 4 (LTC1565-31), PIN 4 (LT1812) AND
RESISTOR R2 SHOULD BE GROUNDED
6
4
R2
0.1µF
V–
–5V
0.1µF
100pF
1565-31 TA10
9
LTC1565-31
U
TYPICAL APPLICATIO S
Simple Pulse Shaping Circuit for Single 5V Operation, 1.25Mbps 2 Level Data
5V
1.25Mbps
DATA
1
2
4.99k
+IN
–IN
+OUT
–OUT
8
VOUT+
7
VOUT–
LTC1565-31
3
0.1µF
4
GND
V–
V+
SHDN
6
5V
5
500mV/DIV
4.99k
4.99k
0.1µF
15645-31 TA04
250ns/DIV
1565-31 TA05
Simple Pulse Shaping Circuit for Single 5V Operation, 2Mbps (1Msps) 4 Level Data
5V
4.99k
4.99k
1
10k
2
D0
4.99k
–IN
+OUT
–OUT
8
VOUT+
7
VOUT–
LTC1565-31
3
0.1µF
+IN
500mV/DIV
D1
1Msps
DATA
4
GND
V–
V+
SHDN
6
5
5V
0.1µF
15645-31 TA06
200ns/DIV
10
1565-31 TA07
LTC1565-31
U
TYPICAL APPLICATIO S
Narrowband Cellular Base Station Receiver
0°
LTC1565-31
LPF
ADC
I
RF/IF
SECTION
90°
LO
Q
DSP
90°
LTC1565-31
LPF
ADC
1565-31 TA03
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
8
7
6
5
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
0°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
2
3
4
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SO8 1298
11
LTC1565-31
U
TYPICAL APPLICATIO
Selective 620kHz CDMA Filter
R5
1k
5V
R4
1.13k
C6
0.1µF R6
1k
C3
18pF
R1
562Ω
R2
562Ω
1
R3
1.24k
2
VIN1
3
C1
150pF
C2
1000pF
R7
562Ω
R8
562Ω
8
U1
LT1813
4
C4
18pF
7
1
C5
180pF
2
6
FGND 3
5
C7
0.1µF
R9
1.24k
4
+IN
+OUT
–IN
–OUT
U2
LTC1565-31
V+
GND
V–
SHDN
R11
1k
VIN2
R10
1.13k
8
VOUT1
7
VOUT2
6
C8
0.1µF
5
15645-31 TA11
5V
R12
1k
Frequency Response
0
–6
GAIN (dB)
–12
–18
–24
–30
–36
–42
–48
100k
1M
FREQUENCY (Hz)
1565 TA12
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1560-1
1MHz/500kHz Continuous Time, Low Noise, Lowpass Elliptic Filter
fCUTOFF = 500kHz or 1MHz
LTC1562/LTC1562-2
Universal 8th Order Active RC Filters
fCUTOFF(MAX) = 150kHz (LTC1562),
fCUTOFF(MAX) = 300kHz (LTC1562-2)
LTC1563-2/LTC1563-3
4th Order Active RC Lowpass Filters
fCUTOFF(MAX) = 256kHz
LTC1569-6/LTC1569-7
Self Clocked, 10th Order Linear Phase Lowpass Filters
fCLK/fCUTOFF = 64/1, fCUTOFF(MAX) = 75kHz (LTC1569-6)
fCLK/fCUTOFF = 32/1, fCUTOFF(MAX) = 300kHz (LTC1569-7)
12
Linear Technology Corporation
156531f LT/LCG 1000 4K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 2000
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