hip6301vcbza-t Intersil Corporation, hip6301vcbza-t Datasheet - Page 17

• Manufacturer Part Number: hip6301vcbza-t
• Description: Microprocessor Core Voltage Regulator Multiphase Buck Pwm Controller
• Manufacturer: Intersil Corporation

Small values of output inductance can cause excessive
power dissipation. The HIP6301V and HIP6302V are
designed for stable operation for ripple currents up to twice
the load current. However, for this condition, the RMS
current is 115% above the value shown in the following
MOSFET Selection and Considerations section. With all else
fixed, decreasing the inductance could increase the power
dissipated in the MOSFETs by 30%.
Input Capacitor Selection
The important parameters for the bulk input capacitors are
the voltage rating and the RMS current rating. For reliable
operation, select bulk input capacitors with voltage and
current ratings above the maximum input voltage and
largest RMS current required by the circuit. The capacitor
voltage rating should be at least 1.25 times greater than the
maximum input voltage and a voltage rating of 1.5 times is
a conservative guideline. The RMS current required for a
multi-phase converter can be approximated with the aid of
Figure 15.
1.0
0.8
0.6
0.4
0.2
FIGURE 14. RIPPLE CURRENT vs DUTY CYCLE
0
0
3 CHANNEL
0.1
4 CHANNEL
DUTY CYCLE (V
0.2
17
SINGLE
CHANNEL
2 CHANNEL
0.3
O
/V
IN
)
0.4
0.5
First determine the operating duty ratio as the ratio of the
output voltage divided by the input voltage. Find the current
multiplier from the curve with the appropriate power
channels. Multiply the current multiplier by the full load
output current. The resulting value is the RMS current rating
required by the input capacitor.
Use a mix of input bypass capacitors to control the voltage
overshoot across the MOSFETs. Use ceramic capacitance for
the high frequency decoupling and bulk capacitors to supply
the RMS current. Small ceramic capacitors should be placed
very close to the drain of the upper MOSFET to suppress the
voltage induced in the parasitic circuit impedances.
For bulk capacitance, several electrolytic capacitors
(Panasonic HFQ series or Nichicon PL series or Sanyo
MV-GX or equivalent) may be needed. For surface mount
designs, solid tantalum capacitors can be used, but caution
must be exercised with regard to the capacitor surge current
rating. These capacitors must be capable of handling the
surge-current at power-up. The TPS series available from
AVX, and the 593D series from Sprague are both surge
current tested.
0.5
0.4
0.3
0.2
0.1
FIGURE 15. CURRENT MULTIPLIER vs DUTY CYCLE
0
0
4 CHANNEL
0.1
DUTY CYCLE (V
0.2
3 CHANNEL
SINGLE
CHANNEL
0.3
O
/V
IN
2 CHANNEL
)
December 27, 2004
0.4
FN9034.2
0.5