HIP6301EVAL2 Intersil, HIP6301EVAL2 Datasheet - Page 14

• Manufacturer Part Number: HIP6301EVAL2
• Description: EVALUATION BOARD HIP6301
• Manufacturer: Intersil

Specifications of HIP6301EVAL2

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 1.6V
• Current - Output: 54A
• Voltage - Input: 5V, 12V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: HIP6301
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Frequency - Switching: -

the sampled current (I
current (I
Where: I
Example: Using the previously given conditions, and
For I
Then I
As discussed previously, the voltage drop across each Q2
transistor at the point in time when current is sampled is
r
PHASE node, is applied through the R
HIP6301 ISEN pin. This pin is held at virtual ground, so the
current into ISEN is:
Example: From the previous conditions,
where I
I
r
Then: R
I
Short circuit I
Channel Frequency Oscillator
The channel oscillator frequency is set by placing a resistor,
R
showing the relationship between frequency, F
resistor R
to place this resistor next to the pin.
Layout Considerations
MOSFETs switch very fast and efficiently. The speed with
which the current transitions from one device to another
causes voltage spikes across the interconnecting
impedances and parasitic circuit elements. These voltage
spikes can degrade efficiency, radiate noise into the circuit
and lead to device overvoltage stress. Careful component
layout and printed circuit design minimizes the voltage
spikes in the converter. Consider, as an example, the turnoff
transition of the upper PWM MOSFET. Prior to turnoff, the
upper MOSFET was carrying channel current. During the
turnoff, current stops flowing in the upper MOSFET and is
picked up by the lower MOSFET. Any inductance in the
switched current path generates a large voltage spike during
the switching interval. Careful component selection, tight
layout of the critical components, and short, wide circuit
I
I
R
SAMPLE
CURRENT TRIP
DSON
DS(ON)
SENSE
SAMPLE
T
ISEN
, to ground from the FS/DIS pin. Figure 10 is a curve
LT
n = 4
SAMPLE
(Q2) x I
=
LT
= 100A,
ISEN
=
LT
(Q2)
LT
(
------------------------------------------------------------------ -
n = the number of channels
T
=
I
. To avoid pickup by the FS/DIS pin, it is important
(
------------------------------------------------------------------ -
SAMPLE
) by:
= total load current
I
----------------------------------------------------------------------------------- -
I
------- -
SAMPLE
LT
n
LT
SAMPLE
= 25.49A
+
(
V
= 100A,
= 25.49A,
= 4mΩ
= 2.04K and
= 165%
= 165A.
50µA
(
R
)r
IN
6L
)r
ISEN
DS ON
)V
DS ON
SAMPLE
) F
(
(
. The voltage at Q2’s drain, the
CORE
(
SW
)
(
) V
)
Q2
(
14
(
Q2
–
) can be related to the load
3V
IN
)
)
)
CORE
ISEN
2
resistor to the
SW,
and
HIP6301
HIP6301
traces minimize the magnitude of voltage spikes. Contact
Intersil for evaluation board drawings of the component
placement and printed circuit board.
There are two sets of critical components in a DC-DC
converter using a HIP6301 controller and a HIP6601B gate
driver. The power components are the most critical because
they switch large amounts of energy. Next are small signal
components that connect to sensitive nodes or supply critical
bypassing current and signal coupling.
The power components should be placed first. Locate the
input capacitors close to the power switches. Minimize the
length of the connections between the input capacitors, C
and the power switches. Locate the output inductors and
output capacitors between the MOSFETs and the load.
Locate the gate driver close to the MOSFETs.
The critical small components include the bypass capacitors
for VCC and PVCC on the gate driver ICs. Locate the bypass
capacitor, C
device. It is especially important to locate the resistors
associated with the input to the amplifiers close to their
respective pins, since they represent the input to feedback
amplifiers. Resistor R
should also be located next to the associated pin. It is
especially important to place the R
respective terminals of the HIP6301.
A multi-layer printed circuit board is recommended. Figure 11
shows the connections of the critical components for one output
channel of the converter. Note that capacitors C
could each represent numerous physical capacitors. Dedicate
one solid layer, usually the middle layer of the PC board, for a
ground plane and make all critical component ground connections
1,000
500
200
100
50
20
10
5
2
1
10
FIGURE 10. RESISTANCE R
20
CHANNEL OSCILLATOR FREQUENCY, F
BP
, for the HIP6301 controller close to the
50
T
100
, that sets the oscillator frequency
200
500 1,000
SEN
T
vs FREQUENCY
resistor(s) at the
2,000
IN
SW
and C
December 27, 2004
(kHz)
5,000 10,000
OUT
FN4765.6
IN
,