TDA8933B Datasheet, PDF (8/42 Pages) NXP Semiconductors – Class D audio amplifier

NXP Semiconductors
R_osc = oscillator resistor (Ω) (on pin OSCREF)
550
f_osc
(kHz)
450
TDA8933B
Class D audio amplifier
010aaa531
350
250
25
30
35
40
45
R_osc (kΩ)
Fig 4. Oscillation frequency as a function of R_osc
Table 5 summarizes how to configure the TDA8933B in master or slave configuration.
For device synchronization see Section 14.6.
Table 5. Master or slave configuration
Configuration
Pin
OSCREF
Master
Slave
R_osc > 25 kΩ to V_SSD(HW)
R_osc = 0 Ω; shorted to V_SSD(HW)
OSCIO
output
input
8.4 Protections
The following protections are implemented in the TDA8933B:
• Thermal Foldback (TF)
• OverTemperature Protection (OTP)
• OverCurrent Protection (OCP)
• Window Protection (WP)
• Supply voltage protections
– UnderVoltage Protection (UVP)
– OverVoltage Protection (OVP)
– UnBalance Protection (UBP)
• Electro Static Discharge (ESD)
The behavior of the device under the different fault conditions differs according to the
protection activated and is described in the following sections.
8.4.1 Thermal Foldback (FT)
If the junction temperature of the TDA8933B exceeds the threshold level (T_j > 140 °C), the
gain of the amplifier is decreased gradually to a level where the combination of
dissipation (P) and the thermal resistance from junction to ambient (R_th(j-a)) results in a
junction temperature of around the threshold level.
TDA8933B_1
Preliminary data sheet
Rev. 01 — 23 October 2008
© NXP B.V. 2008. All rights reserved.
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