TK70001M TOKO [TOKO, Inc], TK70001M Datasheet - Page 7

• Manufacturer Part Number: TK70001M
• Description: SINGLE INPUT, TWO OUTPUT SOLID STATE SWITCH
• Manufacturer: TOKO [TOKO, Inc]

measurements should allow for the ambient temperature
of the PCB. The value obtained from P
derating factor. The PCB mounting pad should provide
maximum thermal conductivity in order to maintain low
device temperatures. As a general rule, the lower the
temperature, the better the reliability of the device. The
thermal resistance when mounted is expressed as follows:
For Toko ICs, the internal limit for junction temperature is
150 C. If the ambient temperature (T
P
simple way to determine P
the output side is shorted. Input current gradually falls as
temperature rises. You should use the value when thermal
equilibrium is reached.
The range of usable currents can also be found from the
graph below.
Procedure:
1) Find P
2) P
3) Plot P
4) Connect P
5) In design, take a vertical line from the maximum
6) Read off the value of P
January 1999 TOKO, Inc.
D
is the value when the thermal sensor is activated. A
with a straight line.
operating temperature (e.g., 75 C) to the derating
curve.
vertical line intersects the derating curve. This is taken
as the maximum power dissipation, D
D1
D PD
P D
T
150 C = 0
0
is taken to be P
(mW)
jA
j
DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)
D1
= 0
D
= 125 C/ P
against 25 C
jA
D1
x P
25
3
6
to the point corresponding to the 150 C
jA
D
+ T
x P
50
D
D
A
D
x (~ 0.8 - 0.9)
+ 25 C
D
D
T A ( C)
against the point at which the
is to calculate V
75
5
D
A
/(150 C - T
) is 25 C, then:
4
PD
.
IN
x I
150
IN
A
) is the
when
The maximum operating current is:
BOARD LAYOUT
The copper pattern should be as large as possible.
APPLICATION INFORMATION
INPUT
GND
+
I
450
350
250
150
OUT
50
0
0
SOT-26 POWER DISSIPATION
= (D
SOT-26 BOARD LAYOUT
PD
/ (V
50
IN(MAX)
T A ( C)
MOUNTED AS
SHOWN
- V
FREE AIR
100
+
OUT
CONT 2
)
+
PCB: CLASS EPOXY T=0.8 mM
TK70001
150
OUTPUT 1
OUTPUT 2
CONT 1
Page 7