HIP4082EVAL Intersil, HIP4082EVAL Datasheet - Page 5

• Manufacturer Part Number: HIP4082EVAL
• Description: EVAL BOARD FET DRIVER HIP4082
• Manufacturer: Intersil
• Type: FET Driverr

Specifications of HIP4082EVAL

• Contents: Fully Assembled Evaluation Board
• For Use With/related Products: HIP4082
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

inverter. Ultra-fast recovery, 3A rectifiers (UF5405), rectify
the 60kHz square-wave voltage waveform. Ultra-fast
recovery rectifiers reduce the recovery energy dissipated.
Even ultrafast diodes, such as the UF5405, forced a slight
reduction in the predicted output power rating of the inverter
due to higher than expected recovery energy loss. Addition
of some series impedance between the filter capacitor, C
and the rectifier bridge, possibly even relocation of the shunt
resistor, R
keep this in mind when designing their own solutions.
The choice of square-wave excitation waveform allows a
smaller rectifier filter capacitor to be used, while still
maintaining very low high voltage DC bus ripple.
The second rectifier provides control power to the linear
regulator, which in turn provides regulated 12V
secondary-side control and gate drivers. This voltage varies
from 15V to 23V as the battery voltage varies from 10V to
15V. A second, isolated winding from the transformer excites
this rectifier. Unlike the high voltage rectifier, this rectifier
bridge incorporates 1Ω of series resistance, R
relatively small filter capacitor, C
occurred in the 1A UF4002 rectifiers. Filter ripple is controlled
by the linear regulator, U
current linear regulator provides 12V bias for all of the
secondary-side control, driver ICs, and for MOSFET gate
drive.
Secondary-Side Inverter
The secondary-side inverter functions include the power
MOSFETs Q
and capacitors, the snubber, the current-sensing resistor, the
output choke, the indicator lamp and the filter.
The inverter topology is a full-wave H-bridge and synthesizes
a pseudo sin-wave by alternately switching on Q
positive half sin-waves and Q
waves. Since the inverter requires the ability to regulate the
RMS output voltage over a wide ranging DC battery input
voltage, some means of varying the conduction period of the
Q
The choice of square-wave output over sine-wave output
simplified the pulse-width-modulator (PWM) and minimized
6
-Q
9
and Q
23
, would help to reduce this power. Users should
6
7
-Q
through Q
8
pairs must be implemented.
3
9
, input (test point TP6). The low
, their associated gate resistors
7
5
and Q
9
. No significant heating
8
for negative half sine-
35
DC
, and a
6
Application Note 9611
for all
and Q
9
8
for
,
MOSFET power dissipation. Figure 3 shows the actual
output voltage waveform.
Varying the width of the positive and negative conduction
periods inversely with the voltage level of the high voltage
bus maintains the RMS value of the output waveform
relatively constant.
Phase shifting two nearly perfect square-waves from the left
and right half-bridges making up the inverter produces the
waveforms shown in Figure 3. The left half-bridge includes
MOSFETs Q
MOSFETs Q
common connections (sometimes referred to as the phase
node or phase terminal) of the MOSFET half-bridges appear
as shown in Figure 4.
Trace 1 is the voltage at the phase node of Q
Trace 2 is the voltage at the phase node of Q
vector difference between the two phase node voltages is
the output voltage shown in Figure 3.
The required phase-shift function is implemented by a simple
control circuit. The technique can be expanded to create
sinusoidal or other output waveform types with added
complexity, of course. The control circuits used in this design
will be discussed in the section, “Secondary Inverter Control
Circuits.”
The high voltage output waveform can exhibit a nasty
voltage transient, with the potential to mess up the output
voltage across the connected load and to possibly destroy
the high voltage gate driver, HIP2500, or the secondary-side
inverter MOSFETs. Therefore phase-to-phase and DC bus
snubbers were added. Resistor, R
implement the bus snubber and resistor, R
C
or “AC” snubbers allow their capacitors to completely charge
and discharge each cycle of the switching waveform and at
high switching frequencies will dissipate a lot of power. R
and C
1
27
, comprise the phase-to-phase snubber. Phase-to-phase
CH1 = 50V
27
FIGURE 3. SECONDARY-SIDE BRIDGE OUTPUT
were not used, but space for them was provided.
6
7
and Q
and Q
8
9
. The waveforms generated at the
and the right half-bridge includes
M = 2.5µs
34
and capacitor, C
38
6
7
and capacitor,
and Q
and Q
GLITCH CH1
8
9
23
. The
and
,
38