GS551 DATA SHEET
High Power, Class B
Output Stage
FEATURES
adjustable gain to 48 dB
capable of driving low impedance receiver
low component count, 3 small capacitors and 1 resistor
gain trim can be used as vol. control for reduced noise
minimal start-up transient
no gain expansion
STANDARD PACKAGING
10 pin MICROpac
10 pin PLID
10 pin SLT
Chip (68 x 60 mils)
CIRCUIT DESCRIPTION
The GS551 is a 10 pin, low voltage, class B amplifier which
operates over a battery range of 1.1 VDC to 3 VDC.
The GS551 consists of three gain blocks. The first block is
an inverting amplifier with the gain set by two external
resistors. The gain trim feature can be used as a volume
control in hearing aid applications. The second block is an
inverting unity gain amplifier which serves as a phase
splitter. The outputs from the first and second blocks drive
the differential input of the third block. The third block has
a fixed AC gain of 28 dB when driving a receiver.
The amplifier has internal compensation eliminating the
need for a capacitor across the receiver. Two ground pins
are available for "Star" grounding to reduce any second
order harmonic distortion introduced by ground line resistance.
REFERENCE
VOLTAGE
C
- B
- A
GND 1
4
2
9
GND 2
7
8 3
1
10
6
5
A IN
A OUT
V
B
C OUT 2
C OUT 1
VREF
DEC 1
DEC 2
U.S. Patent No. 4,719,430
Other Patents Pending
BLOCK DIAGRAM
Revision Date: January 2001
Document No. 510 - 31 - 04
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: hipinfo@gennum.com
2
510 - 31 - 04
REFERENCE
VOLTAGE
C
- B
- A
R
S
0.1
10k
100k
4
2
9
7
8 3
0.047
0.047
1
10
6
V
B
= 1.3VDC
5
R
L
= 400
V
O
R
B
= 4.7
1 kHz
C
S
I
OUT
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Gain
A
V
V
O
=0.707 V
RMS
46
48
50
dB
Amplifier Current
I
AMP
120
220
335
A
Transducer Current
I
TRANS
120
250
390
A
Input Referred Noise
IRN
NFB
0.2 to 10 kHz at 12 dB/Oct
-
1.3
2.5
V
Total Harmonic Distortion
V
O
=0.707 V
RMS
-
0.25
1.3
%
V
O
=1.3 V
RMS
-
0.3
1.5
%
Stable with R
B
to
R
STAB
R
B
=22
-
-
22
Maximum Output Current
I
OUT
V
P8
=0
-
>35
-
mA
PARAMETER
VALUE/UNITS
Supply Voltage
5 VDC
Operating Temperature
-10 to +40
C
Storage Temperature
-20 to +70
C
ABSOLUTE MAXIMUM RATINGS
Fig. 1 Test Circuit
CAUTION
CLASS 1 ESD SENSITIVITY
5
10
1
6
PIN CONNECTION
A IN
A OUT
DEC 1
GND 1
C OUT 1
VB
VREF
DEC 2
GND 2
COUT 2
All parameters remain as shown in Test Circuit unless otherwise stated in "Conditions" column
Conditions: Frequency = 1 kHz, Temperature = 25
C, Supply Voltage V
B
= 1.3 VDC
ELECTRICAL CHARACTERISTICS
THD
All resistors in ohms,all capacitors in farads
unless otherwise stated
510 - 31 - 04
3
Base Current
Compensation
7
6
2
4
5
1
9
2
3
10
6
8
Fig. 2 GS551 Functional Schematic
Fig. 3 Application Circuit
REFERENCE
VOLTAGE
C
- B
0.1
10k
R
VC
100k
4
2
9
7
8 3
0.047
0.047
1
10
6
1.3 VDC
5
- A
GS551
LC506
REGULATOR
+
_
30k
230
R
GT
50k
1.0
0.1
4.7
R
S
3.9k
5
4
2
3
1
CI2960
All resistors in ohms,all capacitors in farads unless otherwise stated
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510 - 31 - 04
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.
REVISION NOTES:
Changes to standard packaging information.
GENNUM CORPORATION
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
GENNUM JAPAN CORPORATION
C-101, Miyamae Village, 2-10-42 Miyamae, Suginami-ku, Tokyo 168-0081,
Japan Tel. +81 (3) 3334-7700 Fax: +81 (3) 3247-8839
Fig. 7 Gain vs Supply Voltage
R
VC
=47k
R
VC
=10k
R
VC
=3.3k
R
VC
=100k
R
VC
=22k
INPUT (dBV)
-130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10
C
S
=0.22
F
C
S
=0.1
F
C
S
=0.033
F
C
S
=0.047
F
20 200 2k 20k
FREQUENCY (Hz)
Fig. 5 Closed Loop Frequency Response
at Various C
S
Values (R
S
=3.92k)
Fig. 4 I/O Characteristics at Various
Gain Settings (R
S
=3.92k)
4
2
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
-20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
Fig. 9 Amplifier Current vs Temperature
0 100 200 300 400 500 600 700 800 900 1000
Fig. 6 Power Outout vs Load Resistance
at 7% Distortion, R
B
=0
, V
B
=1.35V
.8 .9 1 1.1 1.2 1.3 1.4
SUPPLY VOLTAGE (VDC)
LOAD RESISTANCE (
)
10
5
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-20 -10 0 10 20 30 40 50
TEMPERATURE (
C)
TEMPERATURE (
C)
-20 -10 0 10 20 30 40 50
0.10
0.08
0.06
0.04
0.02
0
-0.02
-0.04
-0.06
-0.08
-0.10
Fig. 8 Gain vs Temperature
OUTPUT (
dBV)
RELATIVE AMPLIFIER CURRENT (
A)
RELATIVE GAIN (
d
B
)
RELATIVE OUTPUT (dB
)
POWER OUTPUT (
m
W
)
RELATIVE GAIN (
d
B
)
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 August 1988 Gennum Corporation. All rights reserved. Printed in Canada.
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