Dual, Continuous, Analog Highpass Filter LF580 DATA SHEET FEATURES DESCRIPTION • only 2 small capacitors required The LF580 continuous analog filter consists of two second order (12 dB/oct), tunable (0.2 to 10 kHz) highpass Butterworth filter blocks. • 200 to 10 kHz adjustable corner frequency • dual 12 dB/Oct Butterworth filter (24 dB/Oct cascaded) Tracking and corner frequency of each block are controlled by a single potentiometer. Cascading the two blocks together results in a single 24dB/oct high pass filter requiring only two external 0.001 µF capacitors for the filter response. • 1.1 to 3.0 VDC operating range • adjustable by a single potentiometer The output noise of each filter stage is typically 5.6µV. Cascading the two filter blocks together will produce a noise level which is VN = (V N1) 2 + (VN2)2 STANDARD PACKAGING • 8 pin MICROpac • 8 pin PLID ® • Chip (66 x 61mils) Where VN is the total output noise of both filters, VN1 and VN2 is the noise of each filter. To improve the signal-to-noise ratio of the filter the LF580 should be placed after a preamplifier, provided that the signal level does not exceed the maximum signal capability of 50mVRMS VB 4 8 + AIN 0.001 + 5 0.001 A B _ _ BOUT CONTROL 1.8k 7 6 AOUT BIN 3 CONTROL 1 GND All resistors in ohms, all capacitors in microfarads unless otherwise stated BLOCK DIAGRAM Revision Date: January 2001 Document No. 500 - 73 - 08 GENNUM CORPORATION P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3 tel. +1 (905) 632-2996 Web Site: www.gennum.com E-mail: [email protected] PIN CONNECTION ABSOLUTE MAXIMUM RATINGS PARAMETER VALUE/UNITS Supply Voltage TOP VIEW 5 V DC Operating Temperature Range V -10°C to 50° C Storage Temperature Range 5 4 B B CONTROL B N/C A -40°C to 100° C 1 GND 8 A CAUTION CLASS 1 ESD SENSITIVITY OUT IN OUT IN ELECTRICAL CHARACTERISTICS Conditions: Frequency = 1 kHz, Temperature = 25°C, Supply Voltage VB = 1.3 V Parameter Symbol Insertion Loss Conditions VIN =1 VRMS Note 1 Current Drain IT RCNT = 100 kΩ Corner Frequency fC VIN =1 VRMS Distortion THD VIN =1.25 VRMS VB = 3.0VDC SR Typ Max Units 2 3 dB 280 370 µA 1900 Hz 200 Note 2 Ouput Noise Supply Rejection Min 1300 1650 - 2 5 % Note 3 - 8 10 µV Note 4 - 45 56 dB All parameters and switches remain as shown in Test Circuit unless otherwise stated in "Conditions" column Notes 1: Insertion Loss = 20 Log(VOUT/VIN)-12 2: a) measure output voltage VOUT1 (RCNT =100kΩ) b) measure output voltage VOUT2 (R CNT =10.274kΩ) fC = 1000 x 2 (VOUT1 / VOUT2) 3: Output Noise = VOUT /100, filter bandwidth 200Hz to 10kHz at 12dB/Oct 4: VB modulated with 1VRMS at 1 kHz Supply Rejection = 20 Log (VOUT)-40 RB=4.7 0.001 VB=1.3 VDC +15 VDC 7 1.82k 150 6 0.001 1.0 8 ATTENUATOR 28dB 4 LF580 3 1 -15 VDC 82.1 100k VIN RL=10k RCNT=100k 1000 10 All resistors in ohms, all capacitors in microfarads unless otherwise stated in conditions column Fig. 1 Test Circuit 500 - 73 - 08 VOUT + IC1 40.0 dB _ 5 2 4 0.001 0.001 2 1 1.8k 7 8 5 6 3 All resistors in ohms, all capacitors in microfarads unless otherwise stated Fig. 2 Functional Schematic 1.3 VDC 4 1/ GL504 2 1/ GL504 2 6 RMIC 1.0 RPULL 0.001 8 + 0.001 0.22 5 7 _ + A 0.001 _ 5 0.1 3 B 8 - B 0.033 EP3075 1.0 - A RCLIP 47k CONTROL 1.8k 4 LF580 7 6 3 0.001 RCNT 10k 100k 1.5nF 1 1 2 RMPO 10k RVC All resistors in ohms, all capacitors in microfarads unless otherwise stated Fig. 3 GL504-LF580 Application Circuit 3 500 - 73 - 08 24 2 RCNT=10K RCNT=100K 22 RCNT=1K 0 20 -1 18 -2 16 THD (%) RELATIVE OUTPUT (dB) 1 -3 -4 -5 14 12 10 -6 8 -7 6 -8 4 -9 2 0 -10 100 1K 10K 100K 10 20 FREQUENCY (Hz) 40 50 60 70 80 90 100 INPUT (mVDC) Fig. 4 Frequency Response at Various RCNT Values Fig. 5 Total Harmonic Distortion vs Input Level (measured at Pin 7) 20K 400 10K 380 CURRENT DRAIN (µA) CORNER FREQUENCY (Hz) 30 1K 360 340 320 300 280 100 10 100 1K 10K 260 100 100K 10000 CORNER FREQUENCY (Hz) CONTROL RESISTANCE RCNT (Ω) Fig. 7 Current Drain vs Corner Frequency Fig. 6 Corner Frequency vs Control Resistance GENNUM CORPORATION DOCUMENT IDENTIFICATION: DATA SHEET The product is in production. Gennum reserves the right to make changes at any time to improve reliability, function or design, in order to provide the best product possible. MAILING ADDRESS: P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3 Tel. +1 (905) 632-2996 Fax +1 (905) 632-2814 SHIPPING ADDRESS: 970 Fraser Drive, Burlington, Ontario, Canada L7L 5P5 REVISION NOTES: GENNUM JAPAN CORPORATION Changes to standard packaging information C-101, Miyamae Village, 2-10-42 Miyamae, Suginami-ku, Tokyo 168-0081, Japan Tel. +81 (3) 3334-7700 Fax: +81 (3) 3247-8839 Gennum Corporation assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. © Copyright October 1987 Gennum Corporation. All rights reserved. 500 - 73 - 08 4 Printed in Canada.