Adjustable Analog Highpass Filter GH580 - DATA SHEET FEATURES DESCRIPTION • 200 to 8 kHz adjustable corner frequency The GH580 is a single, second order (12 dB/Oct) continuous high pass filter with an adjustable corner frequency (ƒC) from 200 to 8 kHz. Adjustment of ƒC is accomplished with a single 100 kΩ potentiometer connected from pin 3 to ground. • 12 dB/oct Butterworth filter • low current drain (175 µA typical) • two on chip 1 nF capacitors The bias circuitry is operated from an on chip voltage regulator providing good supply rejection down to 1.1 V. • low noise and distortion • 1.1 to 3.0 VDC operation The two integrated 1 nF capacitors have parasitic diodes connected in parallel. This necessitates that the DC voltage at pin 6 be greater that 400 mV and less than VB and that pins 8 and 7 be no greater than approximately 400 mV DC. STANDARD PACKAGING • 8 pin PLID® The GH580 has a dynamic range of approximately 80 dB. • Chip (66 x 61 mils) VB 4 VREG 8 + A IN + A 1n A OUT _ CP+ 6 + CP- 5 1n 7 CONTROL 1 GND 3 RCNT BLOCK DIAGRAM Revision Date: January 2001 Document No. 520 - 50 - 05 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] ABSOLUTE MAXIMUM RATINGS PIN CONNECTION PARAMETER VALUE/UNITS Supply Voltage 5 V DC VB Power Dissipation 25 mW RCNT Operating Temperature Range -10°C to +40° C NC Storage Temperature Range -20°C to +70° C GND 5 4 A OUT CP+ CP- 1 8 A IN CAUTION CLASS 1 ESD SENSITIVITY ELECTRICAL CHARACTERISTICS Conditions: Frequency = 1 kHz, Temperature = 25°C, V = 1.3V B PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS IAMP 120 175 210 µA Bias Voltage (Pin 6) VP6 - 100 - mV Bias Voltage (Pin 8) VP8 - 350 - mV SW1 to closed, VIN = 40 mVRMS - 1.7 2.0 dB SW1 to closed, VIN = 0 mVRMS - 5 7 µV - 1 5 % Amplifier Current Insertion Loss ILOSS Output Noise ONOISE NFB 200 Hz to 10 kHz at 12dB/oct Distortion THD SW1 to closed, VIN = 50 mVRMS Supply Rejection (Pin 4 to Pin 5) PSRR Note 1, Pin 4 to Pin 5 48 56 - dB ƒC Note 2, RCNT = 10.27k 1300 1650 1900 Hz Corner Frequency All parameters and switches remain as shown in Test Circuit unless otherwise stated in "Conditions" column Notes: 1. V modulated with 1kHz B 2. F C = 1000 x 2A ; A = (ILOSS - 20 LOG (V OUT /0.04))/12 VB=1.3VDC IAMP 4 VREG 8 + + 1µ0 A 1n0 _ SW1 V OUT 5 6 1.8K 7 1 3 VIN 1kHz RCNT 100K All resistors in ohms, all capacitors in farads unless otherwise stated Fig. 1 Test Circuit 520 - 50 - 05 RL=10K CONTROL + 1n0 2 4 1n 2 1 1.8K 5 6 7 8 3 1n All resistors in ohms, all capacitors in farads unless otherwise stated Fig. 2 Functional Schematic 1.3 VDC 4 RMIC 1µ0 8 RP1 + + 1n0 MIC 0µ1 2 4 VREG 3 -A _ 6 A 5 0µ1 10K -C 5 + 1n0 RP2 1/ 1/ 2 GK504 RGT 1 EP 3075 1µ0 CONTROL 7 1n5 33n -B 10 2 GK504 1k8 GH580 1 3 RCNT 100K 100K RVC 100K 9 33n 8 7 6 RMPO 10K All resistors in ohms, all capacitors in farads unless otherwise stated Fig. 3 Typical Hearing Instrument Application 3 520 - 50 - 05 2 16 0 14 -4 12 -6 10 THD (%) RELATIVE OUTPUT (dB) -2 -8 -10 8 -12 6 -14 4 -16 2 -18 0 -20 20 200 2k 10 20k 20 50 60 70 80 Fig. 5 Total Harmonic Distortion vs Input Level Frequency Response at Various RCNT Values 215 10k 210 205 CURRENT DRAIN (µA) CORNER FREQUENCY (Hz) 40 INPUT (mVRMS) FREQUENCY (Hz) Fig. 4 30 1k 200 195 190 185 180 175 100 10 100 1k 10k 170 100k 200 1k CONTROL RESISTANCE (Ω) 8k CORNER FREQUENCY (Hz) Fig. 6 Corner Frequency vs Control Resistance Fig. 7 Current Drain vs Corner Frequency 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 November 1991 Gennum Corporation. All rights reserved. 520 - 50 - 05 4 Printed in Canada.