HIP4080A/81AEVALZ Intersil, HIP4080A/81AEVALZ Datasheet - Page 10

• Manufacturer Part Number: HIP4080A/81AEVALZ
• Description: DEMO BOARD FOR HIP4081A
• Manufacturer: Intersil

Specifications of HIP4080A/81AEVALZ

• Main Purpose: Power Management, H Bridge Driver (Internal FET)
• Utilized Ic / Part: HIP4080A, HIP4081A
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Other names: HIP4080A/81AEVAL; HIP4080A/81AEVAL; Q2670719

Figure 11 shows that the high voltage level-shift current
varies directly with switching frequency. This result should
not be surprising, since Equation 6 can be rearranged to
show the current as a function of frequency, which is the
reciprocal of the switching period, 1/T. The test circuit of
Figure 10 measures quiescent leakage current as well as
the switching component. Notice that the current increases
somewhat with applied bus voltage. This is due to the finite
output resistance of the level-shift transistors in the IC.
Layout Issues
In fast switching, high frequency systems, poor layout can
result in problems. It is crucial to consider PCB layout. The
HIP4080A pinout configuration encourages tight layout by
placing the gate drive output terminals strategically along the
C
FIGURE 10. HIGH VOLTAGE LEVEL-SHIFT CURRENT TEST
L
FIGURE 11. HIGH VOLTAGE LEVEL-SHIFT CURRENT vs
= GATE LOAD CAPACITANCE
1000
500
200
100
50
20
10
5
2
1
1
100K
12V
CIRCUIT
2
FREQUENCY AND BUS VOLTAGE
100K
5
SWITCHING FREQUENCY (kHz)
10
1
2
3
4
5
6
7
8
9
10
BHB
HEN
DIS
V
OUT
IN+
IN-
HDEL
LDEL
AHB
SS
10
20
(0VDC TO 80VDC)
BHO
AHO
BHS
BLO
ALO
AHS
BLS
ALS
V
V
80V
60V
40V
20V
50
DD
CC
20
19
18
17
16
15
14
13
12
11
V
100
BUS
200
A
Application Note 9404
- +
500
I
S
C
C
12V
L
L
1000
right side of the chip (pin 1 is in the upper left-hand corner).
This provides for short gate and source return leads
connecting the IC with the power MOSFETs.
Minimize the series inductance in the gate drive loop by
running the lead going out to the gate of the MOSFETs from
the IC over the top of the return lead from the MOSFET
sources back to the IC by using a double-sided PCB if
possible. The PC board separates the traces and provides a
small amount of capacitance as well as reducing the loop
inductance by reducing the encircled area of the gate drive
loop. The benefit is that the gate drive currents and voltages
are much less prone to ringing which can similarly modulate
the drain current of the MOSFET. The following table
summarizes some of the layout problems which can occur
and the corrective action to take.
Layout Problems and Effects
The Bootstrap circuit path should also be short to minimize
series inductance that may cause the voltage on the boot-
strap capacitor to ring, slowing down refresh or causing an
overvoltage on the bootstrap bias supply.
A compact power circuit layout (short circuit path between
upper/lower power switches) minimizes ringing on the phase
lead(s) keeping BHS and AHS voltages from ringing
excessively below the V
excessive charge extraction from the substrate and possible
malfunction of the IC.
Excessive gate lead lengths can cause gate voltage ringing
and subsequent modulation of the drain current, thereby
amplifying the Miller Effect.
Bootstrap circuit path
too long
Lack of tight power
circuit
circuit path between
upper/lower
switches)
Excessive gate lead
lengths
PROBLEM
layout
power
(long
Inductance may cause voltage on boot-
strap capacitor to ring, slowing down
refresh and/or causing an overvoltage
on the bootstrap bias supply.
Can cause ringing on the phase lead(s)
causing
excessively below the V
causing excessive charge extraction
from
malfunction of the IC.
Can cause gate voltage ringing and
subsequent modulation of the drain
current and impairs the effectiveness of
the sink driver from minimizing the
miller effect when an opposing switch is
being rapidly turned on.
SS
terminal which can cause
the
BHS
substrate
EFFECT
and
AHS
and
SS
December 11, 2007
possible
to
terminal
AN9404.3
ring