LTC1560-1 1MHz/500kHz Continuous Time, Low Noise, Lowpass Elliptic Filter + either 500kHz (Pin 5 to V ) or 1MHz (Pin 5 to V ). When FEATURES programmed for 1MHz, the passband ripple is typically n 5th Order, 1MHz Elliptic Filter in SO-8 Package 0.2dB up to 0.55f and 0.3dB to 0.9f . The CUTOFF CUTOFF n Pin Selectable 1MHz/500kHz Cutoff Frequency transition band gain is 24dB at 1.4f and 51dB at CUTOFF n Signal-to-Noise Ratio (SNR): 75dB 2f . Stopband attenuation is 63dB at 2.43f and CUTOFF CUTOFF n Signal-to-Noise Ratio with 63dB THD: 69dB above, remaining at least 60dB to 10MHz with proper n Passband Ripple (f = 1MHz): 0.3dB CUTOFF board layout. When the LTC1560-1 is programmed for n Stopband Attenuation Better Than 60dB f = 500kHz, the filter response closely follows the CUTOFF n No External Components Required 1MHz case with the exception of passband flatness near the cutoff frequency the gain at f is 1.3dB. CUTOFF U APPLICATIONS The LTC1560-1, unlike other high frequency filters, is designed for low noise and low distortion. With a 1V RMS n Antialiasing Filters input signal, the signal-to-noise ratio is 69dB and the THD n Smoothing or Reconstruction Filters is 63dB. The maximum SNR of 75dB is obtained with a n Communication Filters 2.1V input signal. This results in 46dB THD. RMS The LTC1560-1 operates with 5V supplies, has a power DESCRIPTION saving mode and is available in an SO-8 surface mount package. The LTC 1560-1 is a 5th order, continuous-time, lowpass filter. The elliptic transfer function of the LTC1560-1 was Other cutoff frequencies from 450kHz to 1.5MHz can be carefully chosen to reach a compromise between selectiv- obtained. Demo board DC135A is available for the ity, for antialiasing applications, and transient response. LTC1560-1. For more information please contact LTC The filter cutoff frequency, f , is pin selectable to Marketing. CUTOFF , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION Frequency Response 10 1MHz/500kHz Elliptic Lowpass Filter 0 1 8 10 GND V V OUT OUT 20 2 7 V (OR 5V) V SHDN 30 IN IN LTC1560-1 40 3 6 + GND V 5V 50 0.1F 0.01F 4 5 60 5V V 0.5f /f C C 70 0.1F 0.01F 5V 80 f = 1MHz/500kHz 1MHz CUTOFF 90 5V 0.1 110 500kHz FREQUENCY (MHz) 1560-1 TA01 1560-1 TA02 sn15601 15601fs 1 GAIN (dB) U ULTC1560-1 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION + Total Supply Voltage (V to V ) ............................. 12V TOP VIEW ORDER PART Power Dissipation............................................. 400mW NUMBER GND 1 8 V OUT Burn-In Voltage ................................................... 5.5V V 2 7 SHDN IN LTC1560-1CS8 Operating Temperature Range + GND 3 6 V LTC1560-1IS8 LTC1560-1C ........................................... 0 C to 70 C V 4 5 0.5f f C/ C LTC1560-1I ....................................... 40 C to 85 C S8 PART MARKING S8 PACKAGE Maximum Junction Temperature ......................... 150 C 8-LEAD PLASTIC SO 15601 Storage Temperature Range ................. 65 C to 150 C T = 150 C, q = 125 C/ W JMAX JA 15601I Lead Temperature (Soldering, 10 sec).................. 300 C Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS V = 5V, T = 25 C, Pin 5 = 5V (f = 1MHz), Pin 7 = 0V unless otherwise specified. S A CUTOFF PARAMETER CONDITIONS MIN TYP MAX UNITS Operating Supply Voltage Range 4.5 5.0 5.5 V Passband Gain (f = 1MHz) V = 0.5V ,f = 20kHz 0.17 dB CUTOFF IN RMS IN f = 100kHz l 0.3 0.18 0.6 dB IN f = 300kHz 0.08 dB IN f = 550kHz (Gain Relative to 100kHz) l 0.35 0.05 0.3 dB IN f = 850kHz (Gain Relative to 100kHz) l 0.8 0.3 0 dB IN f = 950kHz (Gain Relative to 100kHz) l 3.0 0.6 0.5 dB IN f = f = 1MHz (Gain Relative to 100kHz) l 5.0 1.0 1.0 dB IN CUTOFF Transition Band Gain (Note 1) V = 0.5V ,f = 1.4MHz l 24 18 dB IN RMS IN f = 1.9MHz 42 dB IN f = 2.0MHz 51 dB IN Stopband Gain (f = 1MHz) (Note 2) f = 2.44MHz l 70 65 dB CUTOFF IN f = 3.0MHz 68 dB IN f = 6.0MHz 66.1 dB IN Passband Gain (f = 500kHz) f = 100kHz, Pin 5 = 5V 0.14 dB CUTOFF IN f = f = 500kHz l 4 1.6 0.5 dB IN CUTOFF f = 1.4MHz 45 dB IN Output Voltage Swing R = 5k 2.20 3V L R = 5k l 1.75 V L Output DC Offset (V ) 250 mV OS Power Supply Current (I ) l 22 29 mA S Power Supply Current in Shutdown Mode Pin 7 at 5V 1 mA Total Output Noise V (Pin 2) Tied to Ground, f = 1MHz, BW = 2MHz 350 m V IN CUTOFF RMS V (Pin 2) Tied to Ground, f = 0.5MHz, BW = 1MHz 322 m V IN CUTOFF RMS Total Harmonic Distortion (THD) V = 1V , f = 200kHz, f = 1MHz, BW = 1MHz 63 dB IN RMS IN CUTOFF f = 300kHz, f = 1MHz, BW = 1MHz 61 dB IN CUTOFF f = 1MHz, f = 1MHz, BW = 2MHz 62 dB IN CUTOFF f = 300kHz, f = 0.5MHz, BW = 1MHz 62 dB IN CUTOFF f = 500kHz, f = 0.5MHz, BW = 1MHz 63 dB IN CUTOFF Input Resistance (R ) l 68 10 kW IN The l denotes specifications which apply over the full operating connection diagram, Figure 2. A small resistor (e.g. 100W ) can also be temperature range. used instead of the buffer to isolate any high capacitive load (C > 10pF) L from the filter output. Note 1: To properly measure high frequency characteristics of the filter, a noninverting output buffer is recommended as shown on the demo board Note 2: The stopband gain at 2.44MHz is guaranteed by design. sn15601 15601fs 2 U W U W U WW