SGSC34119 Datasheet, PDF (5/9 Pages) SeCoS Halbleitertechnologie GmbH – Low Power Audio Amplifier

Elektronische Bauelemente
SGSC34119
Low Power Audio Amplifier
POWER DISSIPATION
Figures 8 to 10 indicate the device dissipation (within the IC) for various combinations of V_CC, R_L, and load power. The
maximum power which can safely be dissipated within the SGSC34119 is found from the following equation: P_D =
(140°C -T _A)/θ_JA where T_A is the ambient temperature; and θ_JA is the package thermal resistance (100°C /W for th e
standard DIP package.)
The power dissipated within the SGSC34119, in a given application, is found from the following equation:
P_D = (V_CC x I_CC) + (I_RMS x V_CC) – (R_L x I_RMS2) where I_CC is obtained from Figure 19; and I_RMS is the RMS current at the
load; and RL is the load resistance.
Figures 8 to 10, along with Figures 11 to 13 (distortion curves), and a peak working load current of 200 mA, define the
operating range for the SGSC34119. The operating range is further defined in terms of allowable load power in Figure
14 for loads of 8.0Ω, 16Ω and 32Ω. The left (ascending) portion of each of the three curves is defined by the power level
at which 10% distortion occurs. The center flat portion of each curve is defined by the maximum output current capability
of the SGSC34119. The right (descending) portion of each curve is defined by the maximum internal power dissipation
of the IC at 25°C. At higher ambient temperatures, the maximum load power must be reduced according to the above
equations. Operating the device beyond the current and junction temperature limits will degrade long term reliability.
LAYOUT CONSIDERATIONS
Normally a snubber is not needed at the output of the SGSC34119, unlike many other audio amplifiers. However, the
PC board layout, stray capacitances, and the manner in which the speaker wires are configured, may dictate otherwise.
Generally, the speaker wires should be twisted tightly, and not more than a few inches in length.
CHARACTERISTICS CURVE
17-Dec-2009 Rev. A
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