LTC1064-4 Low Noise, 8th Order, Clock Sweepable Cauer Lowpass Filter FEATURES DESCRIPTIO 8th Order Filter in a 14-Pin Package The LTC 1064-4 is an 8th order, clock sweepable Cauer 80dB or More Stopband Attenuation at 2 f lowpass switched capacitor filter. An external TTL or CUTOFF 50:1, f to f Ratio (Cauer) CMOS clock programs the value of the filters cutoff CLK CUTOFF + 100:1, f to f Ratio (Transitional) frequency. With Pin 10 at V , the f to f ratio is CLK 3dB CLK CUTOFF 135V Total Wideband Noise 50:1 the filter has a Cauer response and with compensa- RMS 0.03% THD or Better tion the passband ripple is 0.1dB. The stopband attenu- 100kHz Maximum f Frequency ation is 80dB at 2 f . Cutoff frequencies up to CUTOFF CUTOFF Operates up to 8V Power Supplies 100kHz can be achieved. With Pin 10 at V , the f to CLK Input Frequency Range up to 50 Times the Filter f ratio is 100:1, the filter has a transitional Butterworth- 3dB Cutoff Frequency Cauer response with lower noise and lower delay nonlinearity than the Cauer response. The stopband U attenuation at 2.5 f is 92dB. Cutoff frequencies up to 3dB APPLICATIO S 50kHz can be achieved. Antialiasing Filters The LTC1064-4 features low noise and low harmonic Telecom Filters distortion even when input voltages up to 3V are RMS Sinewave Generators applied. The LTC1064-4 overall performance competes , LTC and LT are registered trademarks of Linear Technology Corporation. with equivalent multiple op amp active realizations. The LTCMOS is a trademark of Linear Technology Corporation. LTC1064-4 is pin compatible with the LTC1064-1, LTC1064-2 and LTC1064-3. The LTC1064-4 is manufactured using Linear Technologys TM enhanced LTCMOS silicon gate process. TYPICAL APPLICATIO 8th Order Clock Sweepable Lowpass Elliptic Filter Frequency Response 20 1 14 T = 25C f = 5MHz, 50:1 A CLK INV C R(h, I) C = 30pF, C = 18pF COMP1 COMP2 2 13 0 V V COMP2* IN IN 3 12 AGND V 8V 20 LTC1064-4 4 11 0.1F + CLOCK 8V V f CLK 40 (TTL, 5MHz) 0.1F 5 10 + AGND 50/100 V /V 60 6 9 f = 2MHz, 50:1 CLK COMP1* V V OUT OUT 80 7 8 INV A NC f = 1MHz, 100:1 CLK 100 1064 TA01 1k 10k 100k 1M FREQUENCY (Hz) * FOR FREQUENCIES ABOVE 20kHz AND MINIMUM PASSBAND RIPPLE REFER TO THE PIN DESCRIPTION SECTION FOR COMPENSATION GUIDELINES. 1064-4 TA01b NOTE:THE POWER SUPPLIES SHOULD BE BYPASSED BY A 0.1F CAPACITOR CLOSE TO THE PACKAGE. BYPASSING PIN 10 WITH 0.1F CAPACITOR REDUCES CLOCK FEEDTHROUGH. THE CONNECTION BETWEEN PINS 7 AND 14 SHOULD BE PHYSICALLY DONE UNDER THE PACKAGE. 10644fb 1 V /V (dB) OUT IN U ULTC1064-4 ABSOLUTE AXI U RATI GS (Note 1) + Total Supply Voltage (V to V ) ............................ 16.5V Lead Temperature (Soldering, 10 sec).................. 300C + Input Voltage at Any Pin ......V 0.3V V V +0.3V Operating Temperature Range IN Power Dissipation.............................................. 400mW LTC1064-4M (OBSOLETE) ............... 55C to 125C Storage Temperature Range ................. 65C to 150C LTC1064-4C ....................................... 40C to 85C UUW PACKAGE/ORDER I FOR ATIO TOP VIEW ORDER PART ORDER PART R(h, I) TOP VIEW INV C 1 14 NUMBER NUMBER COMP2 V 2 13 IN INV C 1 16 R(h, I) V AGND 3 12 LTC1064-4CN LTC1064-4CSW V 2 15 COMP2 IN + f V 4 11 CLK AGND 3 14 V RATIO + AGND 5 10 V 4 13 NC V COMP1 6 9 OUT AGND 5 12 f CLK NC INV A 7 8 NC 6 11 RATIO COMP1 7 10 NC N PACKAGE 14-LEAD PDIP INV A 8 9 V OUT T = 110C, = 70C/W JMAX JA SW PACKAGE J PACKAGE 16-LEAD PLASTIC (WIDE) SO 14-LEAD CERDIP LTC1064-4MJ LTC1064-4CJ T = 150C, = 90C/W JMAX JA OBSOLETE PACKAGE Consider the N14 Package for Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = 7.5V, 50:1, f = 1MHz, f = 20kHz, R1 = 10k, TTL clock input A S CLK C level unless otherwise specified. PARAMETER CONDITIONS MIN TYP MAX UNITS Passband Gain Referenced to 0dB, 1Hz to 0.05f 0.5 0.1 dB CUTOFF Gain TempCo 0.0002 dB/C Passband Edge Frequency, f 20 1% kHz C Gain at f Referenced to Passband Gain, f = 20kHz 0.4 0.7 dB C C 3dB Frequency 50:1 (Cauer Response) 21.5 kHz 100:1 (Transitional Response) 10 kHz Passband Ripple (Note 2) 0.1f to 0.95f Referenced to Passband Gain 0.15 0.6 dB C C Stopband Attenuation At 1.7f 56 60 dB CUTOFF Stopband Attenuation At 2f 80 dB CUTOFF + Input Frequency Range 50:1, Pin 10 at V 0f kHz CLK 100:1, Pin 10 at V 0f /2 kHz CLK Output Voltage Swing and V = 2.37V 1.1 V S Operating Input Voltage Range V = 5V 3.1 V S = 7.5V 5.0 V V S Total Harmonic Distortion V = 5V, Input = 1V at 1kHz 0.015 % S RMS V = 7.5V, Input = 3V at 1kHz 0.03 % S RMS Wideband Noise V = 5V, Input = GND 1Hz to 999kHz 120 V S RMS V = 7.5V, Input = GND 1Hz to 999kHz 135 V S RMS 10644fb 2 U WWW