hip1020 Intersil Corporation, hip1020 Datasheet - Page 5

• Manufacturer Part Number: hip1020
• Description: Single, Double Or Triple-output Hot Plug? Controller
• Manufacturer: Intersil Corporation

NOTES:
The MOSFETs in Table 1 were selected based on the
assumption that at most 2% the of the 5V or 3.3V-bus
voltage could appear across the 5V or 3.3V MOSFET, and
that at most 4% of the 12V-bus voltage could appear across
the 12V MOSFET. The worst-case voltage drop occurs
during a 100µs current transient given in the Maximum-
Peak-Current column. Longer transients may not be
tolerable by the MOSFET depending on its junction
temperature prior to the transient.
In most cases, the given Mounting-Pad Area is required to
achieve the Maximum-Average-Current rating. It assumes 1-
oz. copper, zero air flow, and an ambient temperature not
exceeding 50
area of a rectangle encompassing the MOSFET package
and its leads. The r
reached thermal equillibrium at the Maximum-Average-
Current. In some cases, the thermal capabilities as well as
r
copper, air flow, or lower ambient temperature.
Protection from Unwanted Turn On
A dv/dt-activated clamp circuit is internally connected to
LGATE (pin 4), and is active when the chip is not powered. It
is activated when the voltage on either LGATE or HGATE
rises too quickly, and it immediately provides a low-
impedance ground path for current from either gate pin.
The purpose of the dv/dt-activated clamp circuit is to prevent
unwanted turn on of the power MOSFETs during a hot
insertion event. When a Device-Bay peripheral is inserted
into the bay, the power pins on the peripheral are brought
into contact with the already-energized mating contacts in
the bay. This results in a very fast-rising voltage edge on the
drains of the power MOSFETs which can inject current
through the gate-to-drain capacitance and briefly turn on the
DS(ON)
4. Maximum-Average-Current level meets or exceeds the Device-Bay specified level for a 30s “peak”.
5. Maximum-Peak-Current level meets or exceeds the Device-Bay specified level for a 100µs “transient”.
HUF76113T3ST
HUF76105DK8
HUF76113DK8
HUF76131SK8
HUF76143S3S
PART NO.
INTERSIL
or
can be improved by using larger pads, heavier
o
C. The Mounting-Pad Area is the approximate
DS(ON)
MOUNTING-PAD
TABLE 1. DEVICE-BAY MOSFET SELECTION GUIDE FOR PERIPHERAL-POWER CONTROL
AREA (IN
0.05
0.05
0.08
0.05
0.31
numbers assume the device has
5
2
)
SOT223
TO-263
SO-8
SO-8
SO-8
PACKAGE
Single
Single
Single
Dual
Dual
HIP1020
r
DS(ON)
(mΩ)
63
51
48
43
40
37
17
16
15
7
power MOSFET. The result is a momentary dip in the rail
voltage which can effect the device’s operation as well as the
operation of any other device already connected and
potentially the host system itself. Without the dv/dt-activated
clamp, a decoupling capacitor would be needed between
each power MOSFET drain and ground using up valuable
board space and adding unnecessary cost. The HIP1020
solves this problem by providing a path for capacitively-
coupled current to reach ground.
Increasing the Rise Time
The HIP1020 has an internal-ramping charge pump that
increases the voltage to the power MOSFETs in a
predictable controlled manner allowing soft turn on of most
types of loads. It is possible that some types of load would
require slower turn on. This could arise when a load has a
large capacitive component or for some other reason
requires an extraordinarily high starting current. Without the
external capacitor, C1 (see Figure 1), the ramp rate is about
5V/ms. A capacitor between HGATE and ground will slow the
rise time of both gate voltages to a rate given by
In Equation 1, C1 is the value of capacitor in Farads required
to achieve a rise rate of dv/dt in V/s, and I
output of pin 4 given in Amperes as shown in the “Electrical
Specifications” section of this data sheet. Figures 2 through
5 show gate voltage waveforms for selected values of C1.
C1
(VOLTAGE)
BUS
=
3.3
3.3
3.3
3.3
12
12
12
5
5
5
I
-------------------- -
HGATE


dv
------
dt


AVERAGE CURRENT
≤3A (Note 4)
≤3A (Note 4)
≤6A (Note 4)
≤5A (Note 4)
≤9A (Note 4)
MAXIMUM
≤1.5A
≤1A
≤1A
≤2A
≤4A
PEAK CURRENT
HGATE
≤11A (Note 5)
≤25A (Note 5)
≤7A (Note 5)
≤6A (Note 5)
≤9A (Note 5)
MAXIMUM
≤1.25A
≤2.5A
≤1.5A
≤2A
≤4A
is current
(EQ. 1)