External Components Description

(Figures 1-5)

Components

Functional Description

1R

B

Prevents current from entering the amplifier’s non-inverting input. This current may pass through to the load

during system power down, because of the amplifier’s low input impedance when the undervoltage circuitry

is off. This phenomenon occurs when the V

2R

i

Inverting input resistance. Along with R

3R

f

Feedback resistance. Along with R

4R

f2

(Note 15)

Feedback resistance. Works with Cf and Rf creating a lowpass filter that lowers AC gain at high

frequencies. The -3dB point of the pole occurs when: (R

πf

Non-Inverting configuration shown in Figure 5.

5C

f

(Note 15)

Compensation capacitor. Works with R

6C

C

(Note 15)

Compensation capacitor. Reduces the gain at higher frequencies to avoid quasi-saturation oscillations of the

output transistor. Also suppresses external electromagnetic switching noise created from fluorescent lamps.

7C

i

(Note 15)

Feedback capacitor which ensures unity gain at DC. Along with R

1/(2

πR

8C

S

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

placement and selection of bypass capacitors.

9R

V

(Note 15)

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

10

R

IN

(Note 15)

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

create a highpass filter at f

πR

the outputs when the inputs are floating. Recommended values are 10k

Ω to 47kΩ. Refer to Figure 5.

11

C

IN

(Note 15)

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

12

R

SN

(Note 15)

Works with C

13

C

SN

(Note 15)

Works with R

pole is set at f

πR

14

L (Note 15)

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 5.

15

R (Note 15)

16

R

A

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

17

C

A

Provides bias filtering for single supply operation.

18

R

INP

(Note 15)

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

19

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

20

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

21

R

M

Mute resistance set up to allow 0.5mA to be drawn from each MUTE pin to turn the muting function off.

→ R

≤ (|V

≥ 0.5mA. Refer to the Mute Attenuation vs Mute

Current curves in the Typical Performance Characteristics section.

22

C

M

Mute capacitance set up to create a large time constant for turn-on and turn-off muting.

23

S

1

Mute switch. When open or switched to GND, the amplifier will be in mute mode.

24

R

OUT

Reduces current flow between outputs that are caused by Gain or DC offset differences between the

amplifiers.

Note 15: Optional components dependent upon specific design requirements.

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