TDA8588J Datasheet, PDF (48/54 Pages) NXP Semiconductors – I2C-bus controlled 4 x 50 Watt power amplifier and multiple voltage regulator

Philips Semiconductors
I²C-bus controlled 4 × 50 Watt power
amplifier and multiple voltage regulator
Product specification
TDA8588J; TDA8588xJ
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.
TDA8588
ACGND
From
microcontroller
2.2 µF
1.7 kΩ ^{0.22 µF}
100 Ω
47 pF
mdb589
Fig.31 Application diagram for beep input.
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_o. Table 11 shows the affect of the output capacitor on the noise figure.
Table 11 Regulator noise figures
REGULATOR
1
2
3
4
5
NOISE FIGURE (µV) at I_REG = 10 mA; note 1
C_o = 10 µF
C_o = 47 µF
C_o = 100 µF
225
195
185
750
550
530
120
100
95
225
195
185
320
285
270
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.32. 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
48