LTC1064-2

LTC1064-2 Low Noise, High Frequency, 8th Order Butterworth Lowpass Filter FEATURES ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO 8th Order Filter in a 14-Pin Package 140kHz Maximum Corner Frequency No External Components 50:1 and 100:1 Clock to Cutoff Frequency Ratio 80µVRMS Total Wideband Noise 0.03% THD or Better Operates from ±2.37V to ±8V Power Supplies The LTC®1064-2 is a monolithic 8th order lowpass Butterworth filter, which provides a maximally flat passband. The attenuation slope is –48dB/octave and the maximum attenuation is in excess of 80db. An external TTL or CMOS clock programs the filter’s cutoff frequency. The clock to cutoff frequency ratio is 100:1 (Pin 10 at V –) or 50:1 (Pin 10 at V +). The maximum cutoff frequency is 140kHz. No external components are needed. The LTC1064-2 features low wideband noise and low harmonic distortion even for input voltages up to 3VRMS. In fact the LTC1064-2 overall performance competes with equivalent multiple op amp RC active realizations. The LTC1064-2 is available in a 14-pin DIP or 16-pin surface mounted SW package. The LTC1064-2 is fabricated using LTC’s enhanced analog CMOS Si-gate process. The LTC1064-2 is pin compatible with the LTC1064-1. , LTC and LT are registered trademarks of Linear Technology Corporation. APPLICATIO S ■ ■ ■ Antialiasing Filters Smoothing Filters Tracking High Frequency Lowpass Filters TYPICAL APPLICATIO 8th Order Clock Sweepable Lowpass Butterworth Filter 1 14 OUT C LTC1064-2 2 13 NC VIN NC 3 8V 4 5 6 7 VOUT/VIN (dB) Measured Frequency Response 0 VS = ± 7.5V –15 –30 AGND V+ AGND NC RIN A V– fCLK 50/100 VOUT NC 12 11 10 9 8 –8V CLOCK = 5MHz –45 –60 –75 –90 –105 1064 TA01a 0 100 NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED BY A 0.1µF CAPACITOR CLOSE TO THE PACKAGE. THE NC PINS 1, 6, 8, AND 13 SHOULD BE PREFERABLY GROUNDED. U 200 300 400 500 FREQUENCY (kHz) 600 700 1064-2 TA01b U U 10642fa 1 LTC1064-2 ABSOLUTE AXI U RATI GS Total Supply Voltage (V + to V –) ............................ 16.5V Power Dissipation .............................................. 400mW Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C PACKAGE/ORDER I FOR ATIO TOP VIEW NC VIN AGND V+ AGND NC RIN A 1 2 3 4 5 6 7 14 OUT C 13 NC 12 V – 11 fCLK 10 50/100 9 8 VOUT NC ORDER PART NUMBER NC 1 2 3 4 5 6 7 8 LTC1064-2CN N PACKAGE 14-LEAD PDIP TJMAX = 150°C, θJA = 110°C/W J PACKAGE 14-LEAD CERDIP OBSOLETE PACKAGE Consider the N14 Package for Alternate Source LTC1064-2MJ LTC1064-2CJ Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS PARAMETER Passband Gain (Note 2) Gain TempCo –3dB Frequency Gain at –3dB Frequency Stopband Attenuation Stopband Attenuation Stopband Attenuation Stopband Attenuation Input Frequency Range Output Voltage Swing and Operating Input Voltage Range Total Harmonic Distortion Wideband Noise CONDITIONS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 7.5V, 100:1, fCLK = 2MHz, R1 = 10k, TTL clock input level unless otherwise specified. MIN ● Referenced to 0dB, 1Hz to 1kHz 100:1 50:1 Referenced to 0dB, fIN = 20kHz At 1.5f –3dB , 50:1, fIN = 60kHz At 2f –3dB , 100:1, fIN = 40kHz At 3f –3dB , 100:1, fIN = 60kHz At 4f –3dB , 100:1, fIN = 80kHz 100:1 50:1 VS = ±2.37V VS = ±5V VS = ±7.5V VS = ±5V, Input = 1VRMS at 1kHz VS = ±7.5V, Input = 3VRMS at 1kHz VS = ±5V, Input = GND 1Hz – 1.99MHz VS = ±7.5V, Input = GND 1Hz – 1.99MHz 2 U U W WW U W (Note 1) Operating Temperature Range LTC1064-2M (OBSOLETE) ............... – 55°C to 125°C LTC1064-2C ....................................... – 40°C to 85°C TOP VIEW 16 OUT C 15 NC 14 V– ORDER PART NUMBER LTC1064-2CSW VIN AGND V+ AGND NC NC RIN A 13 NC 12 fCLK 11 50/100 10 NC 9 VOUT SW PACKAGE 16-LEAD PLASTIC (WIDE) SO TJMAX = 150°C, θJA = 130°C/W TYP 0.0002 20 40 –3 –27 –47 –74 –90 MAX 0.15 UNITS dB dB/°C kHz kHz dB dB dB dB dB kHz kHz V V V –0.5 ● ● ● –2.75 –24 –44 0 0 ● ● ●