STK400-050 Sanyo Semiconductor Corporation, STK400-050 Datasheet - Page 6

• Manufacturer Part Number: STK400-050
• Description: af Power Amplifier (30W + 30W +30W)
• Manufacturer: Sanyo Semiconductor Corporation

External Circuit Diagram
Heat Radiation Design Considerations
The radiator thermal resistance c-a required for total substrate power dissipation Pd in the STK400-050 is determined as:
Condition 1: IC substrate temperature Tc not to exceed 125°C.
Condition 2: Power transistor junction temperature Tj not to exceed 150°C.
Expressions (1) and (2) can be rewritten based on c-a to yield:
The required radiator thermal resistance will satisfy both of these expressions.
From expressions (1)' and (2)', the required radiator thermal resistance can be determined once the following
specifications are known:
The total substrate power consumption when STK400-050 V
signal, is a maximum of 70W (Fig. 1). In general, when this sort of continuous signal is used for estimation of power
consumption, the Pd used is 1/10th of P
Pd x c-a+Ta <125°C ······························· (1)
Pd x c-a+Pd/N x j-c+Ta<150°C·············(2)
•
•
•
Pd=42.5W (1/10 P
c-a<(125–Ta)/Pd ······································(1)'
c-a<(150–Ta)/Pd– j-c/N··························(2)'
Supply voltage
Load resistance
Assured ambient temperature Ta
where Ta is set assured ambient temperature.
where N is the number of power transistors and j-c the thermal resistance per power transistor chip.
However, power transistor power consumption is Pd equally divided by N units.
O
max=during 3W)
O
V
R
max (slight variation depending on safety standard).
L
CC
STK400-050
CC
is ±26 V and R
L
is 6 Ω, for a continuous sine wave
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