HIP6301V, HIP6302V

FN9034 Rev 3.00

Page 15 of 20

May 5, 2008

current component, the sampled current is different from the

average current per phase. Neglecting secondary effects,

n = the number of channels

Example: Using the previously given conditions, and

n= 4

transistor at the point in time when current is sampled is

HIP6301V ISEN pin. This pin is held at virtual ground, so the

current into ISEN is calculated in Equations 6 and 7:

Example: From the previous conditions,

= 100A,

= 25.49A,

= 2.04k and

Channel Frequency Oscillator

The channel oscillator frequency is set by placing a resistor,

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

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 HIP6301V or HIP6302V controller and a

HIP6601 family 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

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

especially important to locate the resistors associated with the

input to the amplifiers close to their respective pins, since they

sets the oscillator frequency should also be located next to the

resistor(s) at the respective ISEN terminals.

n

--------

V

CORE

3V

2

CORE

–

+

6L

 F

SW

 V

IN



------------------------------------------------------------------------------------

=

(EQ. 5)

r

DS ON



-------------------------------------------------------------------

=

(EQ. 6)

r

DS ON



50

A

-------------------------------------------------------------------

=

(EQ. 7)

50

100

10

20

200

500

1k

5k

10k

2k

1

2

5

10

20

50

100

200

500

1,000