07/19/02
IRDCiP2001-B, 500kHz, 60A, 3-phase Synchronous Buck
Converter using iP2001
Overview
In this document, table 1 and figure 1 are provided to enable engineers to
easily evaluate the iP2001 in a 3-phase configuration that is capable of
providing up to 60A in a lab environment without airflow. Figures 3, 4, 5 and
6 and the complete bill of materials in table 2 are provided as a reference
design to enable engineers to very quickly and easily design a 3-phase
converter. In order to optimize this design to your specific requirements
refer to the data sheet for the controller listed in the bill of materials. A variety
of other controllers may also be used, but the design will require layout and
control circuit modifications.
Demoboard Quick Start Guide
Initial Settings:
zThe output is set to 1.7V, but can be adjusted from 1.1 to 1.85V by setting
S1 according to the VID codes provided in Table 1. Droop control is set to 50mV at 60A, but can be adjusted by
following the instructions in the data sheet for the PWM controller.
zThe switching frequency per phase is set to 500kHz with the frequency set resistor R4. This creates an effective
output frequency of 1.5MHz. The graph in figure 1 shows the relationship between R4 and the switching frequency
per phase. This frequency may be adjusted by changing R4 according to this graph; however, extreme changes
from the 500kHz set point may require redesigning the control loop and adjusting the values of input and output
capacitors. Also, refer to the SOA graph in the iP2001 datasheet for maximum operating current at different
frequencies.
Procedure for Connecting and Powering Up Demoboard:
1. Apply input voltage (5-12V) across VIN (TP18) and PGND (TP14). Note that this input source must be applied first during
the power-up sequence.
2. Apply +5V logic power across +5V (TP19) and PGND (TP20).
3. Apply load across VOUT pads (TP10 - TP12) and PGND pads (TP14 - TP16)
4. Set ENABLE high.
5. Monitor switch node signals (optional) via TP6 - TP8.
6. Adjust load accordingly.
iP2001 Recommended Operating Conditions
(refer to the iP2001 datasheet for maximum operating conditions)
Input voltage: 5 - 12V
Output voltage: 1.1 - 1.85V
Output current: 20A per phase, 60A total for 3-phase demo board.
Switching Freq: 500kHz per phase, 1.5MHz effective output frequency.
IRDCiP2001-B
International Rectifier •233 Kansas Street, El Segundo, CA 90245 USA
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