High Power Class B
Output Stage
LC549/LV549/LD549 DATA SHEET
FEATURES
• 40dB of electrical gain
• 1.0 to 1.6 VDC supply operating range
• current trim capability (R
)
T
• high efficiency class B output stage
• may be used with a linear or compression preamplfier
STANDARD PACKAGING
• 8 pin MICROpac (LC549)
• 8 pin MINIpac
• 8 pin PLID® (LC549, LD549)
• Chip (47 x 40 mils) (LC549, LD549)
V
R
B
T
DESCRIPTION
The LC/LV/LD549 is an 8 pin, low voltage, push-pull audio
frequency output stage amplifier with a single unbalanced
input. The circuit utilizes two internal negative feedback
loops to stabilize the DC operating point for temperature
stability and to linearize the transfer function over a wide
dynamic range. The circuit operates near ideal class B
conditions resulting in low distortion and very low quiescent
current, required for extended battery life.
The LC549, LV549 and LD549 differ in only one respect;
the LV549 and LD549 are selected devices which are
capable of delivering from 10 mA to 41 mA and from 36 mA
to 75 mA of output current respectively. These values are
the maximum current drawn with both output stage transistors
in saturation. Thus the LD549 is capable of producing a
high output in a low impedance load, the LV549 is selected
to have lower peak currents, extending the life of the
battery.
6
3
5
OUTPUT 1
INPUT
2
4
1
DEC 1 DEC 2 GND
U.S. Patent No. 4,085,382
Patented in other countries
8
OUTPUT 2
7
BLOCK DIAGRAM
Revision Date: January 2001
GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. (905) 632-2996 fax: (905) 632-5946
Japan Branch: A-302 Miyamae Village, 2-10-42 Miyamae, Suginami-ku Tokyo 168, Japan tel. (03) 3334-7700 fax: (03) 3247-8839
Document No. 500 - 25 - 09
ABSOLUTE MAXIMUM RATINGS
PIN CONNECTION
PARAMETER VALUE & UNITS
Supply Voltage 3 VDC
Power dissipation 60 mW
Operating Temperature -10 to + 40 °C
DEC1
I/P
DEC2
4
R
T
1
5
OUT1
V
B
GND
8
OUT2
Storage Temperature -20 to + 70 °C
CAUTION
CLASS 1 ESD SENSITIVITY
ELECTRICAL CHARACTERISTICS
Conditions: Temperature 25 oC, Supply Voltage VB = 1.3 VDC
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
Gain A
Quiescent Current I
CL
AMP
I
TRANS
I
TOT
Maximum Drive Current V1 = 0V (S2, S3 closed)
Input Impedance 18 27 36 kΩ
V
= 0.707 VRMS 38 40 42 dB
OUT
100 - 400 µA
170 - 370 µA
- 500 770 µA
V4 = 0V LC549 10 35 75 mA
LV549 10 - 41 mA
LD549 36 50 75 mA
Total Harmonic Distortion & Noise THD V
= 0.707 VRMS - 0.5 - %
OUT
V
= 1.3 VRMS - 2.5 5.2 %
OUT
Input Referred Noise IRN NFB 0.2 to 10 kHz at 12 dB/oct (S1 closed) - 1.2 2.5 µV
Start Up Time - - 3 sec
All switches and parameters remain as shown in test circuit unless stated in condition column
START-UP TIME TEST (Refer to Test Circuit)
SEQUENCE CONDITIONS COMMENTS
1 Power Supply Off
2 S1 Closed Removes V
3 S2 / S3 Closed Discharges C2 and C3
4 S1 Open Applies VIN (VIN level is determined from Gain Test)
5 S2 / S3 Open Removes short from C2 and C3
6 Power Supply On
7 Gain must be within specification, within 3 seconds after power supply is turned on
IN
500 - 25 - 09
2
600Ω
1kHz
40dB ATTENUATOR
V
IN
60k
560
39
S1
C1
0.1
R
=
=∞
T
LC/LD549
2
V
=
B
R
400
L
1.3VDC
V
OUT
I
AMP
I
3
6
5
C4
0.047
TRANS
TI
1:1
8
4
7
1
10
All resistors in ohms, all capacitors in µF unless otherwise stated
Gain = 20 Log
VOUT
( ) +40 dB
10
VIN
1
27k
2
3
C2
S2
6.8
Fig. 1 Test Circuit
+
600
C3
6.8
S3
6
8
7
4
All resistors in ohms, all capacitors in farads unless otherwise stated
U.S. Patent No. 4,085,382 - Patented in other countries
+
Fig. 2 Equivalent Circuit
3
5
500 - 25 - 09
V
B=
1.3VDC
(dB)
V
A
41.0
40.2
39.4
38.6
MIC
+
6.8 6.8
V
C=
10k
0.1
0.01
4
3
2
6
LC506
1
5
2.2
G
T
10k
All resistors in ohms, all capacitors in farads unless otherwise stated
Fig. 3 Typical Hearing Aid Circuit
(µA)
Q
I
532
524
516
508
4
1
LC/LD549
2
3
+
6.8
6
5
.0.047
8
7
470 TYP
+
NC
37.8
37.0
0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8
VB (V)
Fig. 4 Volume Gain vs Battery Voltage
800
700
600
(µA)
Q
I
500
400
300
-20 -10 0 10 20 30 40 50 60 70
TEMPERATURE °C
Fig. 6 Quiescent Current vs Temperature
500
492
0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8
(V)
V
B
Fig. 5 Quiescent Current vs Battery Voltage
46
44
42
(dB)
V
40
A
38
36
-20 -10 0 10 20 30 40 50 60 70
TEMPERATURE (°C)
Fig. 7 Gain vs Temperature
500 - 25 - 09
4
12
41
LD
10
40
8
6
4
POWER OUTPUT (mV)
2
-0 200 400 600 800 1k
LC
LOAD RL (Ω)
Fig. 8 Power Output vs Load Resistance
at 7% Distortion RB = 0Ω
550
500
450
400
350
(µA)
Q
I
300
THD<5.2% AT V
250
200
1 10 100 1K
=1.3 VRMS
OUT
RT (kΩ)
Fig. 10 Quiescent Current vs Current Trim Resistor
39
V
=0.707 VRMS
38
37
RELATIVE VOLTAGE GAIN (dB)
36
0.01 0.1 1.0 10 100
OUT
FREQUENCY (kHZ)
Fig. 9 Voltage Gain vs Frequency
40.4
40.2
40.0
(dB)
V
A
39.8
V
=0.707 VRMS
OUT
VB=1.3 V
39.6
0 4 8 12 16 20 24 26
SUPPLY VOLTAGE (V)
Fig. 11 Voltage Gain vs Battery Resistance
DOCUMENT IDENTIFICATION
PRODUCT PROPOSAL
This data has been compiled for market investigation purposes
only, and does not constitute an offer for sale.
ADVANCE INFORMATION NOTE
The product is in a development phase and specifications are
subject to change without notice. Gennum reserves the right to
remove the product at any time. Listing the product does not
constitute an offer for sale.
PRELIMINARY DATA SHEET
The product is in preproduction phase and specifications are
subject to change without notice.
REVISION NOTES
Changes to standard packaging information
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 January 1981 Gennum Corporation. All rights reserved. Printed in Canada.
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.
5
500 - 25 - 09
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