Analog Integrated Circuit Device Data

Freescale Semiconductor

13

34119

FUNCTIONAL DESCRIPTION

FUNCTIONAL INTERNAL BLOCK DESCRIPTION

POWER DISSIPATION

Figures 10 to 12 indicate the device dissipation (within the

The maximum power which can safely be dissipated within

the MC34119 is found from the following equation:

thermal resistance (100

°C/W for the standard DIP package,

and 180

°C/W for the surface mount package.)

The power dissipated within the 34119, in a given

application, is found from the following equation:

Figures 10 to 12, along with Figures 13 to 15 (distortion

curves), and a peak working load current of

±200 mA, define

the operating range for the 34119. The operating range is

further defined in terms of allowable load power in Figure 16

for loads of 8.0

Ω, 16Ω and 32Ω. The left (ascending) portion

which 10% distortion occurs. The center flat portion of each

curve is defined by the maximum output current capability of

the 34119. 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

34119, 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.