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PT2303 V1.2

- 6 -

December, 2007

2W × 2 Class AB Audio Power Amplifier

PT2303

HEAT DISSIPATION

During normal operation, the chip only consumes very little stand-by current. In high output power

conditions, the package temperature will rise. For proper operating temperature, a modest heat sink

mounted on the top side of the chip is required. The thermal resistance requirement of the heat sink

demand may be obtained by the formula below:

With 60% estimated efficiency (eff), PT2303 in 2W + 2W output power dissipation is probably

The maximum chip conjunction temperature is 150℃, Exceed this temperature will damage the chip,

assuming the outside environment air temperature is 50℃. From the chip conjunction dissipation to

external environment thermal resistance

The PT2303 chip conjunction to case thermal resistance

thermal resistance should be:

In normal operating, PT2303 needs at least 2 sq inch PCB for heat dissipate; it should be use whole

copper foil to cover on it for enough heat dissipation space. We suggest using two-layer PCB for better

heat dissipation. The track connected to the output and power pin of IC should be as thick as possible

for better heat dissipation ability. If IC doesn’t have enough heat dissipation space (>1 sq inch), and IC

is always in full power output situation, an additional heat sink should placed on the chip.