MC33298P Freescale Semiconductor, MC33298P Datasheet - Page 23

• Manufacturer Part Number: MC33298P
• Description: IC SWITCH SERIAL OCTAL 20-DIP
• Manufacturer: Freescale Semiconductor
• Type: Low Sider

Specifications of MC33298P

• Input Type: SPI
• Number Of Outputs: 8
• On-state Resistance: 350 mOhm
• Current - Output / Channel: 1A
• Current - Peak Output: 6A
• Voltage - Supply: 9 V ~ 26.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

inches, having double sided circuit traces of 1.0 ounce
copper soldered to each device pin. The board temperature
was measured with thermal couple soldered to the board
surface one inch away from the center of the device. The
ambient temperature of the enclosure was measured with a
second thermal couple located over the center of one inch
distance from device.
THERMAL PERFORMANCE
parameters values for the 33298 in the 20-pin plastic power
DIP and the SOP-24 wide body surface mount package. Pins
5, 6, 15, and 16 of the power DIP package are connected
directly to the lead frame flag. The parameter values
indicated take into account adjacent output combinations.
The characterization was conducted over power dissipation
levels of 0.7 to 17W. The junction-to-ambient temperature
thermal resistance was found to be 37°C/W with a single
output active (31°C/W with all outputs dissipating equal
power) and in conjunction with this, the thermal resistance
from junction to PC board (R
27°C/W (board temperature, measure one inch from device
center). Additionally, the thermal resistance from junction-to-
heatsink lead was found to approximate 10°C/W. Devoting
Analog Integrated Circuit Device Data
Freescale Semiconductor
Figure 22
20 pin Dip
*
illustrates the worst case thermal component
SOP-24L
Package
Ω
= °C/W, F = W s/°C, I PWR = W, and V A = °C
I PWR (Steady State or Transient)
(1.0A = 1.0W of Device Power Dissipation)
R d0
R
(Ω)*
7.0
7.0
DX
Output 0
JUNCTION-BOARD
C d0
0.002
0.002
C
(F)*
DX
Figure 22. Thermal Model (Electrical Equivalent)
R d1
R
(Ω)*
R PKG = R LEADS +R PC Board
PKG
30
33
Output 1
) was found to be
C d1
C
(F)*
0.15
0.2
PKG
R d2
Output 2
C d2
additional PC board metal around the heatsinking pins
improved R
20 of the package connected directly to the lead frame flag.
Characterization was conducted in the same manner as with
the DIP package. The junction-to-ambient temperature
resistance was found to be 40°C/W with a single output active
(34°C/W with all outputs dissipating equal power0 and the
thermal resistance from junction-to-PC board
(R
measure one inch from device center). The junction-to-
heatsink lead resistance was found again to approximate
10°C/W. Devoting additional PC board metal around the
heatsinking pins for this package improved the R
to 31°C/W.
number of outputs enabled at any one time. At 25°C the
R
junction temperature to remain below 150°C, the maximum
available power dissipation must decrease as the ambient
temperature increases.
output limit of current at ambient temperatures necessary
when one, four, or eight outputs are enable ON.
how the R
temperature.
DS(ON)
JUNCTION-BOARD
The SOP-24 package has pins 5, 6, 7, 8, 17, 18, 19, and
The total power dissipation available is dependent on the
Flag Temperature Node
Junction Temperature Node
V D - T D (C°)
(Volts represent Die Surface Temperature)
in 450mΩ with a coefficient of 6500 ppm/°C. For the
Ambient Temperature Node
V A = T A (C°)
(1.0V = 1°C Ambient Temperature)
DS(ON)
C PKG = C FLAG + C PC Board
PKG
from 30° to 28°C/W.
output value is affected by junction
) to be 30°C/W (board temperature,
Output 6
Figure 23
R d6
C d6
FUNCTIONAL DESCRIPTION
and
FAULT LOGIC OPERATION
Output 7
24
R d7
depict the per
25
C d7
pkg
illustrates
from 33°
33298
23