LTC1264-7CN

LTC1264-7 LTC1264-7 Linear Phase, Group Delay Equalized, 8th Order Lowpass Filter FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Steeper Roll-Off Than Bessel Filters High Speed: fC ≤ 200kHz Phase Equalized Filter in a 14-Pin Package Phase and Group Delay Response Fully Tested Transient Response Exhibits 5% Overshoot and No Ringing 65dB THD or Better Throughout a 100kHz Passband No External Components Needed Available in Plastic 14-Pin DIP and 16-Pin SO Wide Packages The LTC1264-7 is a clock-tunable monolithic 8th order lowpass filter with linear passband phase and flat group delay. The amplitude response approximates a maximally flat passband and exhibits steeper roll-off than an equivalent 8th order Bessel filter. For instance, at twice the cutoff frequency, the filter attains 28dB attenuation (vs 12dB for Bessel), while at three times the cutoff frequency, the filter attains 55dB attenuation (vs 30dB for Bessel). The cutoff frequency of the LTC1264-7 is tuned via an external TTL or CMOS clock. The clock-to-cutoff frequency ratio of the LTC1264-7 can be set to 25:1 (pin 10 to V +) or 50:1 (pin 10 to V –). When the filter operates at clock-to-cutoff frequency ratio of 25:1, the input is double-sampled to lower the risk of aliasing. The LTC1264-7 is optimized for speed. Depending on the operating conditions, cutoff frequencies between 200kHz and 250kHz can be obtained. (Please refer to the Passband vs Clock Frequency graphs.) The LTC1264-7 is pin-compatible with the LTC1064-X series. APPLICATIO S ■ ■ ■ Data Communication Filters Time Delay Networks Phase Matched Filters , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATIO 1 VIN 2 3 8V 4 5 6 7 LTC1264-7 14 13 12 11 10 9 8 4-Level PAM Eye Diagram 200kHz Linear Phase Lowpass Filter –8V 8V VOUT 1264-7 TA01 NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED BY A 0.1µF CAPACITOR CLOSE TO THE PACKAGE AND ANY PRINTED CIRCUIT BOARD ASSEMBLY SHOULD MAINTAIN A DISTANCE OF AT LEAST 0.2 INCHES BETWEEN ANY OUTPUT OR INPUT PIN AND THE fCLK LINE. 1V/DIV fCLK = 5MHz fCLK = 5MHz fC = 200kHz 12647fa U 500ns/DIV 1264-7 TA02 U U 1 LTC1264-7 ABSOLUTE AXI U RATI GS (Note 1) Operating Temperature Range LTC1264-7C ...................................... – 40°C to 85°C LTC1264-7M (OBSOLETE) .............. – 55°C to 125°C Lead Temperature (Soldering, 10 sec)................. 300°C Total Supply Voltage (V + to V –) .......................... 16.5V Power Dissipation ............................................. 400mW Burn-In Voltage ................................................... 16.5V Voltage at Any Input ..... (V – – 0.3V) ≤ VIN ≤ (V + + 0.3V) Storage Temperature Range ............... – 65°C to 150°C PACKAGE/ORDER I FOR ATIO TOP VIEW NC VIN GND V+ NC LP (A) RIN (A) 1 2 3 4 5 6 7 14 OUT (C) 13 NC 12 V – 11 fCLK 10 25/50 9 8 VOUT NC ORDER PART NUMBER LTC1264-7CN NC 1 VIN 2 GND 3 V+ 4 N PACKAGE 14-LEAD PLASTIC DIP TJMAX = 110°C, θJA = 65°C/W (N ) J PACKAGE 14-LEAD CERAMIC DIP TJMAX = 150°C, θJA = 65°C/W (J ) LTC1264-7CJ LTC1264-7MJ OBSOLETE PACKAGE Consider the N14 Package for Alternate Source Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS PARAMETER Passband Gain Gain at 0.50 fCUTOFF (Note 4) Gain at 0.75 fCUTOFF Gain at fCUTOFF Gain at 2.0 fCUTOFF Gain with fCLK = 20kHz Gain with fCLK = 400kHz, VS = ± 2.375V Gain with fCLK = 4MHz The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 7.5V, RL = 10k, fCUTOFF = 100kHz or 50kHz, fCLK = 2.5MHz, TTL or CMOS level (maximum clock rise or fall time ≤ 1µs) and all gain measurements are referenced to passband gain, unless otherwise specified. CONDITIONS 0.1Hz ≤ f ≤ 0.25 fCUTOFF fTEST = 25kHz, (f CLK / fC) = 25:1 fTEST = 50kHz, (f CLK / fC) = 25:1 fTEST = 25kHz, (f CLK / fC) = 50:1 fTEST = 75kHz, (f CLK / fC) = 25:1 fTEST = 100kHz, (fCLK / fC) = 25:1 fTEST = 50kHz, (f CLK / fC) = 50:1 fTEST = 200kHz, (fCLK / fC) = 25:1 fTEST = 100kHz, (fCLK / fC) = 50:1 fTEST = 200Hz, (fCLK / fC) = 50:1 fTEST = 8kHz, (f CLK / fC) = 25:1 fTEST = 16kHz, (f CLK / fC) = 25:1 fTEST = 160kHz, VIN = 1VRMS (f CLK / fC) = 25:1, TA = 0°C to 70°C (f CLK / fC) = 25:1 MIN ● ● ● ● ● ● ● ● 2 U U W WW U W TOP VIEW 16 OUT (C) 15 NC 14 V – 13 NC 12 fCLK 11 25/50 10 NC 9 VOUT ORDER PART NUMBER LTC1264-7CSW NC 5 NC 6 LP (A) 7 RIN (A) 8 SW PACKAGE 16-LEAD PLASTIC SO WIDE TJMAX = 110°C, θJA = 85°C/W TYP – 0.10 – 0.15 –1.0 – 3.0 – 3.0 – 28 – 30 – 0.3 0.15 – 2.70 0.00 ± 1.0 MAX 0.50 0.20 0.30 0.1 –1.9 – 2.3 – 20 – 27 0.1 0.5 – 1.4 UNITS dB dB dB dB dB dB dB dB dB dB dB dB dB 12647fa – 0.50 – 0.50 – 0.65 – 1.5 – 3.7 – 4.5 – 34 – 34 – 0.7 – 0.2 – 3.5 ● 3.0 LTC1264-7 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 7.5V, RL = 10k, fCUTOFF = 100kHz or 50kHz, fCLK = 2.5MHz, TTL or CMOS level (maximum clock rise or fall time ≤ 1µs) and all gain measurements are referenced to passband gain, unless otherwise specified. PARAMETER Phase Factor (F ) Phase = 180° – F (f/fC) (Note 2) Phase Nonlinearity (Note 2) CONDITIONS (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1, f ≤ fCUTOFF (fCLK / fC) = 50:1, f ≤ fCUTOFF (fCLK / fC) = 25:1 (fCLK / fC) = 50:1 VS = Single 5V (GND = 2V) VS = ± 5V VS = ± 7.5V 25:1, ± 7.5V, f = fCLK VS = Single 5V VS = ± 5V VS = ± 7.5V VS = ± 2.375V VS = ± 5V VS = ± 7.5V 25:1, VS = ± 5V 50:1, VS = ± 5V 25:1, VS = ± 5V 50:1, VS = ± 5V VS = ± 2.375V VS = ± 5V VS = ± 7.5V Power Supply Range MIN TYP 407 ± 2 388 ± 2 ±1.0 ±1.0 ● ● ELECTRICAL CHARACTERISTICS MAX ● ● 392 374 423 414 ± 2.0 ± 2.0 Group Delay (td) td = (F / 360)(1/fC); (Note 3, 4) Group Delay Ripple (Note 3) 11.3 21.6 ● ● 10.9 20.8 ±1.0 ±1.0 11.7 22.9 ● ● ± 2.0 ± 2.0 Input Frequency Range (Table 9, 10) Maximum fCLK Clock Feedthrough Wideband Noise (1Hz ≤ f < fCLK) Input Impedance Output DC Voltage Swing (Note 5) Output DC Offset (fCLK = 1MHz) Output DC Offset TempCo Power Supply Current (fCLK = 1MHz) 45 ● ● ± 2.0 ± 3.0