TFA9842AJ Philips, TFA9842AJ Datasheet - Page 11

• Manufacturer Part Number: TFA9842AJ
• Description: 7.5W Stereo Power Amplifier
• Manufacturer: Philips

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Philips Semiconductors
TFA9842AJ_1
Preliminary specification
13.1.2 Volume control drive options
13.2.1 Layout and grounding
13.2 Printed-circuit board
To obtain a high-level system performance, certain grounding techniques are essential.
The input reference grounds have to be tied with their respective source grounds and
must have separate tracks from the power ground tracks; this will prevent the large output
signal currents from interfering with the small AC input signals. The small-signal ground
tracks should be physically located as far as possible from the power ground tracks.
Supply and output tracks should be as wide as possible for delivering maximum output
power.
Fig 12. Volume control drive circuit with 3.3 V PWM
Fig 13. Volume control drive circuit with 5 V
PWM
PWM
5 V
1 k
R4
PWM
3.3 V
GND
Rev. 01 — 28 April 2006
R1
10 k
D1
5.6 V
C1
10 F
1 k
R5
001aae338
T1
VC
T2
V
R2
1 k
7.5 W stereo power amplifier with volume control
CC
5 V
T3
R3
1 k
Fig 14. Volume control drive circuit with
R1
10 k
D1
10 V
1 k
R4
potentiometer
T1
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
V
16 k
001aae337
CC
C1
10 F
R5
VC
TFA9842AJ
R6
16 k
C1
10 F
001aae339
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VC