tda8589j NXP Semiconductors, tda8589j Datasheet - Page 49

• Manufacturer Part Number: tda8589j
• Description: I2c-bus Controlled 4 45 Watt Power Amplifier And Multiple Voltage Regulator
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Beep input circuit
Beep input circuit to amplify the beep signal from the microcontroller to all 4 amplifiers (gain = 0 dB). Note that this circuit
will not affect amplifier performance.
Noise
The outputs of regulators 1 to 5 are designed to give very low noise with good stability. The noise output voltage depends
on output capacitor C
Table 11 Regulator noise gures
Note
1. Measured in the frequency range 20 Hz to 80 kHz.
Stability
The regulators are made stable by connecting capacitors to the regulator outputs. The stability can be guaranteed with
almost any output capacitor if its Electric Series Resistance (ESR) stays below the ESR curve shown in Fig.34. If an
electrolytic capacitor is used, its behaviour with temperature can cause oscillations at extremely low temperature.
Oscillation problems can be avoided by adding a 47 nF capacitor in parallel with the electrolytic capacitor. The following
example describes how to select the value of output capacitor.
2004 Feb 24
I
amplier and multiple voltage regulator
2
C-bus controlled 4
REGULATOR
1
2
3
4
5
o
. Table 11 shows the affect of the output capacitor on the noise figure.
45 Watt power
microcontroller
Fig.33 Application diagram for beep input.
C
o
= 10 F
225
750
120
225
320
From
NOISE FIGURE ( V) at I
1.7 k
49
0.22 F
2.2 F
TDA8589
100
ACGND
C
o
= 47 F
195
550
100
195
285
REG
47 pF
= 10 mA; note 1
TDA8589J; TDA8589xJ
C
Product specication
o
= 100 F
185
530
185
270
95