STK400-290 Sanyo Semiconductor Corporation, STK400-290 Datasheet - Page 7

• Manufacturer Part Number: STK400-290
• Description: af Power Amplifier (50W+50W+50W)
• 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 STK400-290 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 STK400-290 V
signal, is a maximum of 105 W (Figure. 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
Pd
•
•
•
Pd = 66.5 W (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
c-a + Ta < 125°C ···························· (1)
c-a + Pd/N
where Ta is the 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
j-c + Ta < 150°C ······(2)
max=during 5 W)
V
R
L
CC
O
max (slight variation depending on safety standard).
STK400-290
CC
is ±32 V and R
L
is 6 Ω, for a continuous sine wave
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