HIP4080A/81AEVALZ Intersil, HIP4080A/81AEVALZ Datasheet - Page 9

• 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

Power Dissipation, the Easy Way
The average power dissipation associated with the IC and
the gate of the connected MOSFETs can easily be
measured using a signal generator, an averaging millimeter
and a voltmeter.
Low Voltage Power Dissipation
Two sets of measurements are required. The first set uses
the circuit of Figure 8 and evaluates all of the low voltage
power dissipation components. These components include
the MOSFET gate charge and internal CMOS charge
transfer losses shown in Equation 5 as well as the quiescent
bias current losses associated with the IC. The losses are
calculated very simply by calculating the product of the bias
voltage and current measurements as performed using the
circuit shown in Figure 8. For measurement purposes, the
phase terminals (AHS and BHS) for both A and B phases
are both tied to the chip common, V
the lower source terminals, ALS and BLS. Capacitors equal
to the equivalent gate-source capacitance of the MOSFETs
are connected from each gate terminal to V
the capacitance chosen comes from the MOSFET
manufacturers data sheet. Notice that the MOSFET data
sheet usually gives the value in units of charge (usually
nano-coulombs) for different drain-source voltages. Choose
the drain-source voltage closest to the particular DC bus
voltage of interest.
Simply substituting the actual MOSFETs for the capacitors,
C
Miller capacitance will not be accounted for. This is because
the drains don’t switch using the test circuit shown in
Figure 8. Also the gate capacitance of the devices you are
using may not represent the maximum values which only the
data sheet will provide.
The low voltage charge transfer switching currents are
shown in Figure 9. Figure 9 does not include the quiescent
bias current component, which is the bias current which
flows in the IC when switching is disabled. The quiescent
bias current component is approximately 10mA. Therefore
the quiescent power loss at 12V would be 120mW. Note that
the bias current at a given switching frequency grows almost
proportionally to the load capacitance, and the current is
directly proportional to switching frequency, as previously
suggested by Equation 5.
L
, doesn’t yield the correct average current because the
9
SS
terminal, along with
SS
. The value of
Application Note 9404
High Voltage Power Dissipation
The high voltage power dissipation component is largely
comprised of the high voltage level-shifter component as
described by Equation 6. All of the difficulties associated with
the time variance of the I
shift voltage, V
avoided. For completeness, the total loss must include a
small leakage current component, although the latter is
usually smaller compared to the level-shifter component.
The high voltage power loss calculation is the product of the
high voltage bus voltage level, V
voltage bus current, I
in Figure 10. Averaging meters should be used to make the
measurements.
20K
20K
FIGURE 8. LOW VOLTAGE POWER DISSIPATION TEST
FIGURE 9. LOW VOLTAGE BIAS CURRENT I
500
200
100
0.5
0.2
0.1
50
20
10
5
2
1
100K
+
I
1
BIAS
12V
A
10,000
3,000
1,000
CIRCUIT
2
SHIFT
100
100K
(LESS QUIESCENT COMPONENT) vs
FREQUENCY AND GATE LOAD
CAPACITANCE
C
HDEL
LDEL
, under the integrand in Equation 6 are
SWITCHING FREQUENCY (kHz)
BHB
AHB
5
HEN
OUT
L
DIS
V
BUS
IN+
IN-
= GATE LOAD CAPACITANCE
SS
10
ON
, as measured by the circuit shown
10
1
2
3
4
5
6
7
8
9
and I
20
HIP4080A
BUS
OFF
50
, and the average high
pulses and the level
100
20
19
18
17
16
15
14
13
12
11
BHO
BHS
BLO
BLS
V
V
ALS
ALO
AHS
AHO
200
DD
CC
December 11, 2007
DD
AND I
500
AN9404.3
1000
CC
C
C
C
C
L
L
L
L