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01-Jun-2002 Rev. A

Page 2 of 6

P arameter

S ymbol

Value

Unit

/www.SeCoSGmbH.com/

Elektronische Bauelemente

Any changing of specification will not be informed individual

this pin (with a 5.0uF capacitor at Pin 2)

on time of the circuit is affected by the

nd resistor set low frequency rolloff and input impedance. The

Supply Voltage

15

V

Power Dissipation

Pd

1.25

W

Input Voltage

-0.4 ~ +0.4

V

Operating Temperature

Topr

0 ~ 70

:

Storage Temperature

Tstg

-65 ~ 150

:

Junction Temperature

Tj

150

:

Parameter

Symbol

Test Conditions

Min

Typ.

Max.

Unit

Operating Supply Voltage

4

-

12

V

Quiescent Current

-

4

8

mA

Output Power

230

480

-

-

-

-

mW

Voltage Gain

10 F form Pin1 to Pin8

-

26

46

-

dB

Bandwidth

BW

-

300

-

kHz

Total Harmonic Distortion

THD

-

0.2

-

%

Power Supply Rejection

Ration

S

=6V

and Pin8 open

-

50

-

dB

Input Resistance

-

50

-

k

Input Bias Current

-

250

-

nA

Note1: All voltages are measured with respect to the ground pin, unless otherwise specified.

Note2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions

for which the device is functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC

electrical specifications under particular test conditions which guarantee specific performance limits. This assumes that the device

is within the Operating Ratings.

Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device

performance.

Note3: For operation in ambient temperatures above 25 : , the device must be derated based on a 150 : maximum junction temperature

and 1) a thermal resistance of 107 : /W, junction to ambient for the dual-in-line package and 2)a thermal resistance of 170 : /W for

the small outline package.

Application Hints

Gina Control

To make the

SPWLM386D a more versatile amplifier, two pins (1 and 8) are provided for gain control. With pins 1 and 8 open the 1.35K

resistor sets the gain at 20 (26dB),If a capacitor is put from pin 1 to 8,bypassing the 1.35k 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) prom 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 15k resistor). For 6 dB effective bass boost: R=15k , the lowest value for

good stable operation in R=10k , if pin 8 is open, If pins 1 and 8 are bypassed then R as low as 2k can be used. This restriction is

because the amplifier is only compensated for closed-loop gains greater than 9.

Input Biasing

The schematic show that both input are biased to ground with a 50k 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

SPWLM386D is higher than 250k 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 10k, then shorting the

unused input to ground will keep the offset low (about 2.5mW at the input, 50mW at the output). For dc source resistance 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

SPWLM386D with higher gains (bypassing the 1.35k resistor between pin1 and 8) it is necessary to bypass the unused

input, preventing degradation of gain and possible instabilities. This is done with a 0.1 F capacitor or a short to ground depending on the

dc source resistance on the driven input.

SPWLM386D

Low Voltage Audio Power

Amplifier