STK401-020 Sanyo Semicon Device, STK401-020 Datasheet - Page 6

• Manufacturer Part Number: STK401-020
• Description: AF Power Amplifier
• Manufacturer: Sanyo Semicon Device

External Circuit Diagram
Heat Radiation Design Considerations
The radiator thermal resistance c-a required for total substrate power dissipation Pd in the STK401-020 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 STK401-020 V
signal, is a maximum of 27.5W (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=15.7W (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 is the thermal resistance per power transistor chip.
However, power transistor power consumption is Pd equally divided by N units.
O
max=during 1.5W)
O
V
R
max (slight variation depending on safety standard).
L
CC
STK401-020
CC
is ±20 V and R
L
is 6 Ω, for a continuous sine wave
No. 4341-6/9