56531I

LTC1565-31 650kHz Continuous Time, Linear Phase Lowpass Filter FEATURES s s s s s s s s s 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 APPLICATIO S s s s s s s 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. TYPICAL APPLICATIO Frequency Response 10 2.0 GAIN 1.9 1.8 1.7 1.6 DELAY 1.5 1.4 1.3 1.2 1.1 1.0 105 106 FREQUENCY (Hz) 0.9 107 1565 G01 Single 5V Supply, Differential 650kHz Lowpass Filter VIN+ VIN– 1 2 +IN –IN +OUT –OUT 8 7 VOUT+ GAIN (dB) VOUT– 5V + 0 –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 104 LTC1565-31 3 0.1µF 4 GND V– V 6 5 5V 0.1µF SHDN 15645-31 TA01 U DELAY (µs) U U 1 LTC1565-31 ABSOLUTE MAXIMUM RATINGS (Note 1) PACKAGE/ORDER INFORMATION TOP VIEW +IN 1 –IN 2 GND 3 V– 4 8 7 6 5 +OUT –OUT V+ SHDN 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 LTC1565-31CS8 LTC1565-31IS8 S8 PART MARKING 156531 56531I S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 80°C/ W (NOTE 4) Consult factory for Military grade parts. The q 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 Operating Supply Voltage 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) VIN = 1VP-P, fIN = 25kHz fIN = 200kHz fIN = 300kHz fIN = 500kHz fIN = 600kHz fIN = 650kHz fIN = 900kHz Ratio of 600kHz Phase/300kHz Phase Noise BW = DC to 2 • fCUTOFF fIN = 100kHz, 1VP-P (Note 2) Maximum Difference Between Pins 7 and 8 VS = 5V VS = ± 5V q q q q q q q q q ELECTRICAL CHARACTERISTICS CONDITIONS MIN 4.75 – 0.3 – 0.2 – 0.7 – 2.2 –4 TYP 0 0 –0.4 –1.6 –3 –11 –36 –72 –13 –101 –150 113 60 36 – 92 2 118 86 MAX 11 0.3 0.1 – 0.1 – 0.95 –2 –7 – 31 UNITS V dB dB dB dB dB dB dB dB Deg Deg Deg Deg Deg Deg Deg µVRMS dB Filter Phase q q – 162 34 – 138 85 Phase Linearity Wideband Noise THD Filter Differential DC Swing q 1.95 2.03 ± 1.4 ± 2.2 0.1 ±1.7 ±2.3 0.3 ± 10 75 145 3 ±5 ±5 ± 1.9 ± 2.5 0.6 Input Bias Current Input Offset Current Input Resistance Input Capacitance Output DC Offset (Note 3) V S = 5V VS = ±5V (Note 5) Common Mode, VIN = 2.5V Differential ± 12 ± 12 2 U W U U WW W VP VP µA nA MΩ MΩ pF mV mV LTC1565-31 The q 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 Output DC Offset Drift Ground Voltage (Pin 3) in Single Supply Applications SHDN Pin Logic Thresholds CONDITIONS V S = 5V VS = ±5V V S = 5V VS = 5V, Minimum Logical “1” VS = 5V, Maximum Logical “0” VS = ±5V, Minimum Logical “1” VS = ±5V, Maximum Logical “0” SHDN Pin Pull-Up Current Power Supply Current Power Supply Current in Shutdown Mode V S = 5V VS = ±5V V S = 5V VS = ±5V Shutdown. Includes SHDN Pull-Up Current VS = 5V VS = ± 5V q q q q q q q q q ELECTRICAL CHARACTERISTICS MIN TYP – 400 – 400 MAX UNITS µV/°C µV/°C 2.49 2.51 2.52 4.2 V V V V V µA µA 3.3 2.9 2.4 5 9 24 25 8 20 31 33 16 40 mA mA 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. TYPICAL PERFOR A CE CHARACTERISTICS Frequency Response 10 0 –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 104 105 106 FREQUENCY (Hz) DELAY GAIN 2.0 1.9 1.8 1.7 1.5 1.4 1.3 1.2 1.1 1.0 107 1565 G01 GAIN (dB) GAIN (dB) UW Passband Gain and Delay vs Frequency 0.5 0 –0.5 –1.0 DELAY (µs) GAIN 5V ± 5V 2.0 1.9 1.8 1.7 DELAY (µs) 1.6 –1.5 –2.0 –2.5 –3.0 –3.5 –4.0 TA = 25°C –4.5 25k DELAY 1.6 1.5 1.4 1.3 1.2 1.1 100k FREQUENCY (Hz) 1.0 1M 1565 G02 0.9 3 LTC1565-31 TYPICAL PERFOR A CE CHARACTERISTICS Passband Gain vs Frequency Over Temperature 0.5 0.4 0.3 0.2 –40°C VS = 5V GAIN (dB) GAIN (dB) GAIN (dB) 0.1 0 –0.1 –0.2 –0.3 –0.4 –0.5 25k 85°C 25°C 100k FREQUENCY (Hz) Common Mode Rejection Ratio 110 VIN = 1VP-P VS = 5V 100 TA = 25°C 90 80 SUPPLY CURRENT (mA) CMRR (dB) 80 70 60 50 103 PSRR (dB) 104 105 106 FREQUENCY (Hz) 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 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. 4 UW 1565 G03 Stopband Gain vs Frequency –40 Stopband Gain vs Frequency Over Temperature –40 VS = 5V –50 –50 –40°C 25°C 85°C –60 VS = 5V –60 –70 –70 –80 VS = ± 5V –80 400k –90 1.5 1.8 2.4 2.1 FREQUENCY (MHz) 2.7 3.0 1565 G04 –90 1.5 1.8 2.4 2.1 FREQUENCY (MHz) 2.7 3.0 1565 G04 Power Supply Rejection Ratio VIN = 200mVP-P VS = 5V TA = 25°C Supply Current vs Temperature 26 70 25 VS = ± 5V 60 50 VS = 5V 24 40 107 1565 G06 30 103 104 105 106 FREQUENCY (Hz) 107 1565 G07 23 –50 –30 30 50 –10 10 TEMPERATURE (°C) 70 90 1565 G08 U U U LTC1565-31 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. BLOCK DIAGRA +IN 1 –IN 2 GND 3 5k SHUTDOWN SWITCH V+ V– 4µA SHUTDOWN V– 4 W U U U + 8 +OUT – + R 7th ORDER LINEAR PHASE FILTER NETWORK OUTPUT BUFFER R – + V+ SHUTDOWN SWITCH – OUTPUT BUFFER 7 –OUT INPUT BUFFERS WITH COMMON MODE TRANSLATION CIRCUIT ~1M 5k 6 V+ ~1M 5 SHDN 1565-31 BD 5 LTC1565-31 APPLICATIONS INFORMATION Interfacing to the LTC1565-31 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. 1 2 +IN –IN +OUT –OUT 8 7 VOUT+ VOUT– 5V 6 5 0.1µF 15645-31 F01 THD (dB) + – VIN+ + – VIN– 3 LTC1565-31 GND V– V+ SHDN 0.1µF 4 DC COUPLED INPUT V + + VIN– VIN (COMMON MODE) = IN 2 V + + VOUT– V+ = VOUT (COMMON MODE) = OUT 2 2 THD (dB) Figure 1 0.1µF 1 2 +IN –IN +OUT –OUT 8 7 VOUT+ VOUT– 5V + + – VIN+ + – VIN– 0.1µF 100k 1µF 100k 3 4 LTC1565-31 GND V– V 6 5 SHDN AC COUPLED INPUT VIN (COMMON MODE) = VOUT (COMMON MODE) = V+ 2 Figure 2 6 U W U U Input Common Mode and Differential Voltage Range 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. –30 –40 VS = ± 5V –50 –60 –70 –80 –90 VIN = 2VP-P fIN = 100kHz –5 –4 –3 –2 –1 0 1 2 3 4 INPUT COMMON MODE VOLTAGE (V) 5 1565-31 F03 Figure 3. THD vs Common Mode Input Voltage –30 VS = 5V –40 –50 –60 –70 VIN = 2VP-P fIN = 100kHz 0.5 3.0 1.0 2.0 2.5 1.5 INPUT COMMON MODE VOLTAGE (V) 3.5 –80 1565-31 F04 Figure 4. THD vs Common Mode Input Voltage 0.1µF 15645-31 F02 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 APPLICATIONS INFORMATION –30 –40 –50 –60 –70 –80 –90 THD: VS = 5V, VCM = 2.5V THD: VS = ± 5V, VCM = 0V SNR fIN = 100kHz THD, SNR (dB) 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. 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 –40 –50 –60 –70 –80 –90 THD: VS = 5V, VCM = 2V THD: VS = ± 5V, VCM = – 0.5V SNR fIN = 100kHz THD (dB) THD, SNR (dB) THD (dB) 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 U W U U Output Common Mode and Differential Voltage Range 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. 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 –10 –20 –30 –40 –50 –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 VIN = 2VP-P 100kHz VS = 5V VIN(CM) = 2V Figure 7. THD vs Common Mode Output Voltage VIN = 2VP-P 100kHz –10 VS = ± 5V VIN(CM) = – 0.5V –20 –30 –40 –50 –60 –70 –80 –90 –4 0 1 2 –3 –2 –1 3 COMMON MODE OUTPUT VOLTAGE (V) 4 0 1565-31 F08 Figure 8. THD vs Common Mode Output Voltage 7 LTC1565-31 APPLICATIONS INFORMATION Output Drive 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. 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 5V ± 5V TYPICAL APPLICATIO S Test Circuit for Single 5V Supply Operation 4.99k 5V 4.99k 0.1µF 6 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 10µF + – 4 3 0.1µF 4.99k 5V 4 –IN –OUT 4.99k 10µF LTC1565-31 GND V+ 6 0.1µF V– SHDN 5 2.49k 5V 1k 5V 0.01µF 0.1µF 6 20Ω 2.2µF 1565-31 TA08 8 + 2.49k 3 4 0.1µF + – 4.99k 2 7 A3 LT1809 6 0.1µF V +/2 1k 3 – 2 + + VCM 2.49k 3 A2 LT1809 6 –VIN/2 + VCM 2 +IN +OUT 7 2.49k 3 – – VIN 4.99k 2 + 2.49k 3 – 2 7 A1 LT®1809 4 2.49k 5V 0.1µF 5V 4.99k 7 +VIN/2 + VCM 1 U W U U U 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. Table 1. Wideband Noise vs Bandwidth, Single 5V Supply BANDWIDTH DC to fCUTOFF DC to 2 • fCUTOFF TOTAL INTEGRATED NOISE 104µVRMS 118µVRMS Table 2. Wideband Noise vs Supply Voltage, fCUTOFF = 650kHz TOTAL INTEGRATED NOISE DC TO 2 • fCUTOFF 118µVRMS 120µVRMS 4.99k 8 2 7 A4 LT1809 4 6 0.1µF VOUT (SINGLE ENDED) 19k 7 A5 LT1812 4 LTC1565-31 TYPICAL APPLICATIO S Single-Ended Input/Output Dual Supply Filter VIN +IN +OUT –IN –OUT LTC1565-31 3 0.1µF –5V 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) 4 V– SHDN 5 GND V+ 6 0.1µF 5V R2 2.49k –5V A Fully Differential Filter with Adjustable Output Common Mode Voltage VIN+* VIN–* 1 +IN +OUT 8 VOUT+ VOUT– 2 –IN –OUT 7 LTC1565-31 3 GND V+ 6 0.1µF –5V 0.1µF 4 V– SHDN 5 5V 5V V+ R1 0.1µF 6 –3V ≤ VOUT(CM) ≤ 3V *–3.4V ≤ VIN(CM) ≤ 2.5V VIN(CM) CAN BE EQUAL OR DIFFERENT FROM VOUT(CM) NOTE: FOR SINGLE 5V SUPPLY OPERATION, PIN 4 (LTC1565-31), PIN 4 (LT1812) AND RESISTOR R2 SHOULD BE GROUNDED 0.1µF 100pF 1565-31 TA10 R2 V– 0.1µF + 3 – 2 7 LT1812 4 –5V + 2 7 2.49k 3 – U 4.99k 5V 4.99k 0.1µF 6 VOUT 1 8 2 7 LT1809 4 0.1µF 1565-31 TA09 VOUT(CM) = V – + (V + – V –)R2 R1 + R2 9 LTC1565-31 TYPICAL APPLICATIO S Simple Pulse Shaping Circuit for Single 5V Operation, 1.25Mbps 2 Level Data 5V 4.99k 1.25Mbps DATA 4.99k 4.99k 3 0.1µF 4 1 2 +IN –IN +OUT –OUT 8 7 VOUT+ LTC1565-31 GND V– V+ SHDN 6 5 0.1µF 15645-31 TA04 5V 500mV/DIV Simple Pulse Shaping Circuit for Single 5V Operation, 2Mbps (1Msps) 4 Level Data 5V 4.99k D1 10k D0 4.99k 3 0.1µF 4 2 7 1Msps DATA 4.99k 1 8 –IN –OUT VOUT– LTC1565-31 GND V– V+ SHDN 6 5 0.1µF 15645-31 TA06 5V 500mV/DIV +IN 10 U VOUT– 250ns/DIV 1565-31 TA05 +OUT VOUT+ 200ns/DIV 1565-31 TA07 LTC1565-31 TYPICAL APPLICATIO S Narrowband Cellular Base Station Receiver RF/IF SECTION PACKAGE DESCRIPTION 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0°– 8° TYP 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 0.016 – 0.050 (0.406 – 1.270) 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. U U 0° 90° 90° LTC1565-31 LPF ADC I LO Q DSP LTC1565-31 LPF ADC 1565-31 TA03 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 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157** (3.810 – 3.988) 1 2 3 4 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC SO8 1298 11 LTC1565-31 TYPICAL APPLICATIO R4 1.13k C3 18pF R1 562Ω VIN1 C1 150pF R7 562Ω VIN2 R10 1.13k C2 1000pF R8 562Ω R9 1.24k R2 562Ω R3 1.24k 1 2 3 4 U1 LT1813 8 7 6 5 C4 18pF GAIN (dB) RELATED PARTS PART NUMBER LTC1560-1 LTC1562/LTC1562-2 LTC1563-2/LTC1563-3 LTC1569-6/LTC1569-7 DESCRIPTION 1MHz/500kHz Continuous Time, Low Noise, Lowpass Elliptic Filter Universal 8th Order Active RC Filters 4th Order Active RC Lowpass Filters Self Clocked, 10th Order Linear Phase Lowpass Filters COMMENTS fCUTOFF = 500kHz or 1MHz fCUTOFF(MAX) = 150kHz (LTC1562), fCUTOFF(MAX) = 300kHz (LTC1562-2) fCUTOFF(MAX) = 256kHz fCLK/fCUTOFF = 64/1, fCUTOFF(MAX) = 75kHz (LTC1569-6) fCLK/fCUTOFF = 32/1, fCUTOFF(MAX) = 300kHz (LTC1569-7) 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com U Selective 620kHz CDMA Filter 5V R5 1k C6 0.1µF R6 1k 1 C5 180pF 2 +IN –IN +OUT –OUT 8 7 VOUT1 VOUT2 FGND 3 C7 0.1µF R11 1k R12 1k 4 U2 LTC1565-31 GND V– V+ SHDN 6 5 5V C8 0.1µF 15645-31 TA11 Frequency Response 0 –6 –12 –18 –24 –30 –36 –42 –48 100k FREQUENCY (Hz) 1565 TA12 1M 156531f LT/LCG 1000 4K • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2000