ETC GH580

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.