TDA8946AJ Datasheet, PDF (15/20 Pages) NXP Semiconductors – 2 x 15 W BTL audio amplifier with DC gain control

Philips Semiconductors
TDA8946AJ
2 x 15 W BTL audio amplifier with DC gain control
4Ω
OUT2 −
220 nF
ON
220
OUT2 +
4Ω
MODE
nF
10 µF
SVR
1
220 nF
4.7
nF
4.7
nF
1
OUT1 −
220 nF
OUT1 +
4Ω
220 nF
220 nF
100 nF
4Ω
IN2 +
IN2 −
IN1 −
IN1 +
GC
SGND
VCC
1000 µF
GND
MGW628
Fig 16. Printed-circuit board layout (single-sided); components view.
14.1.2 Power supply decoupling
Proper supply bypassing is critical for low-noise performance and high supply voltage
ripple rejection. The respective capacitor location should be as close as possible to
the device and grounded to the power ground. Proper power supply decoupling also
prevents oscillations.
For suppressing higher frequency transients (spikes) on the supply line a capacitor
with low ESR - typical 100 nF - has to be placed as close as possible to the device.
For suppressing lower frequency noise and ripple signals, a large electrolytic
capacitor - e.g. 1000 µF or greater - must be placed close to the device.
The bypass capacitor on the SVR pin reduces the noise and ripple on the midrail
voltage. For good THD and noise performance a low ESR capacitor is recommended.
14.2 Thermal behaviour and heatsink calculation
The measured maximum thermal resistance of the IC package, R_th(j-mb) is 2.5 K/W.
A calculation for the heatsink can be made, with the following parameters:
T_amb = 50 °C
V_CC = 18 V and R_L = 8 Ω
T_j(max) = 150 °C
R_th(tot) is the total thermal resistance between the junction and the ambient
including the heatsink. In the heatsink calculations the value of R_th(mb-h) is ignored.
9397 750 09434
Product data
Rev. 01 — 01 March 2002
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
15 of 20