HIP0080AM INTERSIL [Intersil Corporation], HIP0080AM Datasheet - Page 9

• Manufacturer Part Number: HIP0080AM
• Description: Quad Inverting Power Drivers with Serial Diagnostic Interface
• Manufacturer: INTERSIL [Intersil Corporation]

Dissipation In Multiple Outputs
HIP0080, HIP0081The HIP0080 and HIP0081 Power
Drivers have multiple MOS Output Drivers and require
special consideration with regard to maximum current and
dissipation ratings. While each output has a maximum
current specification consistent with the device structure,
all such devices on the chip can not be simultaneously
rated to the same high level of peak current. The total
combined current and the dissipation on the chip must be
adjusted for maximum allowable ratings, given
simultaneous multiple output conditions.
HIP0080, HIP0081For the HIP0081, the maximum positive
output current rating is 2.2A when one output is ON. When
ALL outputs are ON, the rating is reduced to 1.5A because
the total maximum current is limited to 6A. For any given
application, all output drivers on a chip may or may not have a
different level of loading. The discussion here is intended to
provide relatively simple methods to determine the maximum
dissipation and current ratings as a general solution and, as a
special solution, when all switched ON outputs have the same
current loading.
General Solution
HIP0080, HIP0081A general equation for dissipation
should specify that the total power dissipation in a
package is the sum of all significant elements of
dissipation on the chip. However, in Power BiMOS Circuits
very little dissipation is needed to control the logic and
predriver circuits on the chip. The overall chip dissipation
is primarily the sum of the I
channel where the current, I is the output current and the
resistance, R is the NMOS channel resistance, r
each output driver. As such, the total dissipation, P
output drivers is:
D
=
FIGURE 4. SINGLE PULSE ENERGY TEST SHOWING THE
10000
k
1000
=
n
100
1
P
0.1
k
HIP0080 SINGLE PULSE
ENERGY vs TIME
T
NOTE: SAFE OPERATING AREA
AMB
FAILURE BOUNDARY FOR EACH HIP0080 OUT-
PUT STRESSED TO POINT OF FAILURE
= 25
BELOW DOTTED LINE
o
1
C
PULSE WIDTH TIME (ms)
2
R dissipation losses in each
9
10
100
DS(ON)
D
HIP0080, HIP0081
(EQ. 1)
for n
1000
of
HIP0080, HIP0081This expression sums the dissipation, P
of each output driver without regard to uniformity of
dissipation in each MOS channel. The dissipation loss in
an NMOS channel is given in Equation 2 where the current,
I, is determined by the output load when the channel is
turned ON. The channel resistance, r
the circuit design, level of gate voltage and the chip
temperature. Other switching losses may include I
the interconnecting metal on the chip and bond wires of the
package.
HIP0080, HIP0081The temperature rise in the package
due to the dissipation is the product of the dissipation, P
and the thermal resistance,
to-Case). To determine the chip junction temperature, T
given the case (heat sink
heat flow solution is:
HIP0080, HIP0081or:
HIP0080, HIP0081Since this solution relates only to the
package, further consideration must be given to a practical
heat sink. The equation of linear heat flow assumes that
the thermal resistance from Junction-to-Ambient (
the sum of the thermal resistance from Junction-to-Case
and the thermal resistance from Case (heat sink)-to-
Ambient. The Junction-to-Ambient thermal resistance,
is the sum of all thermal paths from the chip junction to the
ambient temperature (T
expressed as:
P
T
T
JA
k
J
C
FIGURE 5. SINGLE PULSE ENERGY TEST SHOWING THE
10000
=
=
=
1000
=
100
I
T
T
2
C
J
JC
0.1
+
–
r
DS ON
P
P
+
HIP0081 SINGLE PULSE
ENERGY vs TIME
T
NOTE: SAFE OPERATING AREA
D
D
AMB
CA
FAILURE BOUNDARY FOR EACH HIP0081 OUT-
PUT STRESSED TO POINT OF FAILURE
JC
JC
= 25
BELOW DOTTED LINE
o
1
C
PULSE WIDTH TIME (ms)
A
) environment and can be
tab
) temperature, T
JC
10
of the package (Junction-
DS(ON)
100
is a function of
C
, the linear
2
R lost in
JA
(EQ. 3A)
(EQ. 2)
(EQ. 3)
) is
(EQ. 4)
1000
JA
D
J
,
k