External Components Description

Components

Functonal Description

1R

B

Prevents currents from entering the amplifier’s non-inverting input which may be passed through to the

load upon power down of the system due to the low input impedance of the circuitry when the

undervoltage circuitry is off. This phenomenon occurs when the supply voltages are below 1.5V.

2R

I

Inverting input resistance to provide AC gain in conjunction with R

at f

3R

F

Feedback resistance to provide AC gain in conjunction with R

4C

Feedback capacitor which ensures unity gain at DC.

5C

S

Provides power supply filtering and bypassing. Refer to the Supply Bypassing application section for

proper placement and selection of bypass capacitors.

6R

V

(Note 14)

Acts as a volume control by setting the input voltage level.

7R

IN

(Note 14)

Sets the amplifier’s input terminals DC bias point when C

to create a highpass filter at f

8C

IN

(Note 14)

Input capacitor which blocks the input signal’s DC offsets from being passed onto the amplifier’s inputs.

9R

SN

(Note 14)

Works with C

The pole is set at f

10

C

SN

(Note 14)

Works with R

11

L (Note 14)

Provides high impedance at high frequencies so that R may decouple a highly capacitive load and

reduce the Q of the series resonant circuit. Also provides a low impedance at low frequencies to short

out R and pass audio signals to the load. Refer to

Figure 4.

12

R (Note 14)

13

R

A

Provides DC voltage biasing for the transistor Q1 in single supply operation.

14

C

A

Provides bias filtering for single supply operation.

15

R

INP

(Note 14)

Limits the voltage difference between the amplifier’s inputs for single supply operation. Refer to the

Clicks and Pops application section for a more detailed explanation of the function of R

16

R

BI

Provides input bias current for single supply operation. Refer to the Clicks and Pops application section

for a more detailed explanation of the function of R

17

R

E

Establishes a fixed DC current for the transistor Q1 in single supply operation. This resistor stabilizes the

half-supply point along with C

Note 14: Optional components dependent upon specific design requirements.

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