vnd920p STMicroelectronics, vnd920p Datasheet - Page 14

• Manufacturer Part Number: vnd920p
• Description: Double Channel High Side Solid State Relay
• Manufacturer: STMicroelectronics

SO-28 Double island PC Board
Thermal calculation according to the PCB heatsink area
R
R
R
R
thA
thB
thC
thj-amb
Chip 1
OFF
ON
ON
ON
= Thermal resistance Junction to Ambient with both chips ON and P
= Thermal resistance Junction to Ambient with one chip ON
= Mutual thermal resistance
Layout condition of R
Cu thickness=35 m, Copper areas: 0.5cm
Vs PCB copper area in open box free air condition
Chip 2
RTHj_am b
OFF
ON
ON
ON
(°C/W)
70
60
50
40
30
20
10
R
R
R
(R
0
thA
thC
thB
thA
x P
x (P
x P
x P
SO-28 DOUBLE ISLAND THERMAL DATA
th
dchip1
dchip2
dchip1
dchip1
and Z
1
+ T
+ T
) + R
+ P
th
T
amb
amb
PCB Cu heatsink area (cm ^2)/island
measurements (PCB FR4 area= 58mm x 58mm, PCB thickness=2mm,
jchip1
dchip2
thC
x P
) + T
2
dchip2
amb
2
, 3cm
+ T
3
amb
2
, 6cm
R
R
R
(R
2
).
thC
thA
thB
thA
x P
x (P
x P
4
x P
dchip1
dchip2
dchip2
dchip1
dchip1
) + R
+ T
+ T
+ P
=P
T
5
jchip2
amb
amb
dchip2
dchip2
thC
x P
) + T
dchip1
6
amb
R
R
R
+ T
thA
thB
thC
amb
P
P
7
dchip1
dchip1
VND920P
Note
=P
P
dchip2
dchip2
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