UNISONIC TECHNOLOGIES CO., LTD LM386
UNISONIC TECHNOLOGIES CO., LTD
LM386
LINEAR INTEGRATED CIRCUIT
LOW VOLTAGE AUDIO POWER
AMPLIFIER
DESCRIPTION

The UTC LM386 is a power amplifier, designed for use in low
voltage consumer applications. The gain is internally set to 20 to keep
external part count low, but the addition of an external resistor and
capacitor between pin 1 and pin 8 will increase the gain to any value
up from 20 to 200 dB.
The inputs are ground referenced while the output automatically
biases to one-half the supply voltage. The quiescent power drain is
only 24 milliwatts when operating from a 6 volt supply, making the
LM386 ideal for battery operation.
FEATURES

*Battery Operation
*Minimum External Parts
*Wide Supply Voltage Range: 4V~12V
*Low Quiescent Current Drain:4mA
*Voltage Gains: 20~200dB
*Ground Referenced Input
*Self-Centering Output Quiescent Voltage
*Low Distortion: 0.2% (Av=20, VS=6V, RL=8Ω, PO=125mW, f=1kHz)

ORDERING INFORMATION
Ordering Number
Lead Free
LM386L-D08-T
-
Halogen Free
LM386G-D08-T
LM386G-S08-R
LM386G-P08-R
Package
Packing
DIP-8
SOP-8
TSSOP-8
Tube
Tape Reel
Tape Reel
MARKING

DIP-8
8
7
6
5
UTC
LM386
1
2
3
4
SOP-8
TSSOP-8
Date Code
L: Lead Free
G: Halogen Free
Lot Code
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Copyright © 2015 Unisonic Technologies Co., Ltd.
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LM386
LINEAR INTEGRATED CIRCUIT

PIN CONFIGURATION

BLOCK DIAGRAM
6
BYPASS
7
15K
-INPUT
15K
GAIN GAIN
8
1
150
2
15K
5
1.35K
3
50K
UNISONIC TECHNOLOGIES CO., LTD
VOUT
+INPUT
50K
4
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VS
GND
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LM386

LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
VCC
VIN
RATINGS
UNIT
15
V
-0.4V ~ +0.4V
V
DIP-8
1250
Power Dissipation
PD
mW
SOP-8
600
TSSOP-8
600
Operating Temperature
TOPR
-25 ~ +85
C
Junction Temperature
TJ
+125
C
Storage Temperature
TSTG
-40 ~ +150
C
Note:1. Absolute maximum ratings are stress ratings only and functional device operation is not implied. The device
could be damaged beyond Absolute maximum ratings.
Supply Voltage
Input Voltage

ELECTRICAL CHARACTERISTICS (TA=25C, unless otherwise specified.)
PARAMETER
Operating Supply Voltage
Quiescent Current
SYMBOL
VS
IQ
Output Power
POUT
Voltage Gain
GV
Bandwidth
BW
Total Harmonic Distortion
THD
Rejection Ratio
RR
Input Resistance
Input Bias Current
RIN
IBIAS
TEST CONDITIONS
MIN
4
TYP
VS=6V, VIN=0
VS=6V, RL=8Ω, THD=10%
250
VS=9V, RL=8Ω, THD=10%
500
VS=6V, f=1kHz
10μF from pin 1 to pin 8
VS=6V , Pin1 and pin 8 open
POUT=125mW, VS=6V, f=1kHz
RL=8Ω pin1 and pin 8 open
VS=6V, f=1kHz, CBYPASS=10μF
pin1and pin 8 open, Referred to output
4
325
700
26
46
300
VS=6V Pin2 and pin 3 open
UNISONIC TECHNOLOGIES CO., LTD
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MAX UNIT
12
V
8
mA
mW
dB
dB
kHz
0.2
%
50
dB
50
250
kΩ
nA
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
LINEAR INTEGRATED CIRCUIT
APPLICATION NOTES
GAIN CONTROL
To make the LM386 a more versatile amplifier, two pins(1and 8) are provided for gain control. With pins 1 and 8
open the 1.35 kΩ resistor sets the gain at 20 (26dB), If a capacitor is put from pin 1 to 8, bypassing the 1.35 kΩ
resistor, the gain will go up to 200(46dB). If a resistor is placed in series with the capacitor, the gain can be set to
any value from 20 to 200. Gain control can also be done by capacitively coupling a resistor (or FET) from pin 1 to
ground.
Additional external components can be placed in parallel with the internal feedback resistors to tailor the gain and
frequency response for individual applications. For example we can compensate poor speaker bass response by
frequency shaping the feedback path. This is done with a series RC from pin 1 to 5 (paralleling the internal 15 kΩ
resistor). For 6 dB effective bass boost: R=15 kΩ, the lowest value for good stable operation is R=10 kΩ, if pin 8 is
open, If pins 1 and 8 are bypassed then R as low as 2 kΩ can be used. This restriction is because the amplifier is
only compensated for closed-loop gains greater than 9.
INPUT BIASING
The schematic shows that both inputs are biased to ground with a 50 kΩ resistor. The base current of the input
transistors is about 250nA, so the inputs are at about 12.5mW when left open. If the dc source resistance driving the
LM386 is higher than 250 kΩ it will contribute very little additional offset (about 2.5mW at the input, 50mW at the
output).If the dc source resistance is less than 10 kΩ, then shorting the unused input to ground will keep the offset
low (about 2.5mV at the input, 50 mV at the output). For dc source resistances between these values we can
eliminate excess offset by putting a resistor from the unused input to ground, equal in value to the dc source
resistance. Of course all offset problems are eliminated if the input is capacitively coupled.
When using the LM386 with higher gains (bypassing the 1.35 kΩ resistor between pins 1 and 8) it is necessary to
bypass the unused input, preventing degradation of gain and possible instabilities. This is done with a 0.1μF
capacitor or a short to ground depending on the dc source resistance on the driven input.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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LM386

LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATIONS CIRCUIT
AM Radio Power
Amplifier
FROM
DETECTOR
Cc
VOL
10KΩ
Vs
10μF
+
0.05μF
R1
10KΩ
2
C1
2200pF
6
-
FERRITE
BEAD
1
250μF
+
8 5
3 +
4
7
47
+10μF
47Ω
+
0.05μF
8Ω
SPEAKER
Notes: 1: Twist Supply lead and supply ground very tightly.
2: Twist speaker lead and ground very tightly.
3: Ferrite bead in Ferroxcube K5-001-001/3B with 3 turns of wire.
4: R1C1 band limits input signals.
5: All components must be spaced very closely to IC.
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Total Harmonic Distortion (%)
Voltage Gain (dB)
Output Voltage (Volts Peak-To-Peak)
Power Supply Rejection (dB)
Supply Current (mA)

Voltage Gain (dB)
LM386
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UNISONIC TECHNOLOGIES CO., LTD
LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS
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LM386
LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS(cont.)

Device Dissipaton vs Output Power 4ΩLoad
Distortion vs Output Power
2.0
10
8
1.8
1.6
Device Dissipation (W)
Total Harmonic Distortion (%)
9
Vs=6V
RL=8Ω
f=1kHz
7
6
5
4
3
2
1.4
Vs=12V
1.2
Vs=9V
0.8
0.6
0
0.001
Vs=6V
0
0.01
0.1
0
1.0
Power Output (Watts)
10%
THD
LEVEL
1.6
Device Dissipation (W)
0.3
0.4
0.5
Device Dissipaton vs Output Power -16ΩLoad
Vs=16V
1.4
1.2
Vs=12V
Vs=9V
0.6
0.4
0.2
Vs=6V
3% THD
LEVEL
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Output Power (W)
Vs=16V
0.8
Device Dissipation (W)
1.8
0
0.2
1.0
2.0
0.8
0.1
Output Power (W)
Device Dissipaton vs Output Power 8ΩLoad
1.0
10%
THD
LEVEL
0.4
0.2
1
3% THD
LEVEL
1.0
3% THD
LEVEL
0.6
Vs=12V
0.4
0.2
10%
THD
LEVEL
Vs=9V
Vs=6V
0
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Output Power (W)
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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www.unisonic.com.tw
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