Datasheet

M_CH1M_CH2
S_CH1
S_CH2−
NOT USED IN3PH
M
R
S
TPS40140
SLUS660H –SEPTEMBER 2005–REVISED JUNE 2013 www.ti.com
5.28.1 BASIC CONFIGURATIONS FOR 2, 4, 6, 8, 12 OR 16 PHASES
The solid square boxes in Figure 5-20 represent the PHSEL pin of the master (M) controller or a
numbered slave controller (S1-S7). The labels on the spokes of the wheels indicate a master Channel 1
and master Channel 2 (M_CH1 and M_CH2) and numbered slaves Channel 1 and slave Channel 2
(Sn_CH1 and Sn_CH2). The Channel 1 and Channel 2 of a given master or slave is always 180° out-of-
phase.
The master and slaves are automatically configured for proper phasing based on the resistor string from
the master to the slaves. All the resistors are 39 kΩ to 41.2 kΩ. Part (A) above shows a single controller
operating two phases 180° out-of-phase. Part (B) above shows four phase operation. This is configured by
connecting a single resistor from the master PHSEL to GND and grounding the slave PHSEL pin. The
individual channels are 90° out-of-phase. Part (C) above shows six phase operation. This is configured by
connecting two resistors from the master PHSEL to GND. The first resistor tap is connected to slave2
PHSEL pin and then grounding the slave1 PHSEL pin. The individual channels are 60°out-of-phase. Part
(D) above shows eight phase operation. This is configured by connecting three resistors from the master
PHSEL to GND. The first resistor tap is connected to slave3 PHSEL pin. The second resistor tap is
connected to slave2 PHSEL pin and then grounding the slave1 PHSEL pin. The individual channels are
45° out-of-phase. Part (F) above shows twelve phase operation. This is configured by connecting two
resistors from the master PHSEL to GND. The master PHSEL pin is also connected to slave5 PHSEL pin.
The first resistor tap is connected to slave2 and slave4 PHSEL pins and then grounding the slave1 and
slave3 PHSEL pins. The individual channels are 30° out-of-phase. Additionally, the ILIM2 pins of slave5,
slave4 and slave3 are left open (internal pull-up) or externally connected to BP5. Part (G) above shows
sixteen phase operation. This is configured by connecting three resistors from the master PHSEL to GND.
The master PHSEL pin is also connected to slave7 PHSEL pin. The first resistor tap is connected to
slave3 and slave6 PHSEL pins. The second resistor tap is connected to slave2 and slave5 PHSEL pins
and then grounding the slave1 and slave4 PHSEL pins. The individual channels are 22.5° out-of-phase.
Additionally, the ILIM2 pins of slave7, slave6, slave5 and slave4 are left open (internal pull-up) or
externally connected to BP5.
5.28.2 CONFIGURING FOR OTHER NUMBER OF PHASES
Configuring for other than 2, 4, 6, 8, 12 or 16 phases is simply a matter of not attaching one or more slave
controllers. The phasing between master and populated slaves is as shown above. For example a 3-
phase system could be configured with a master CH1 and master CH2 and 1 phase of a slave. Referring
to Part (B) above, the 3 phases could be master CH1, master CH2 and slave CH1 or slave CH2 as shown
in Figure 5-21.
Figure 5-21. Phase System: 2 Channels of the Master and 1 Channel of the Slave
The 3-phase system could also be configured with 1 channel of the master and 2 channels of the slave.
Referring to Part (B) above, the 3 phases could be master CH1 or master CH2 and slave CH1 and slave
CH2. In either of these configurations there is 90° between two of the channels and 180° between the
other channel. The unused channel could be another independent output voltage whose clocking would
occupy the phase not used in the 3-phase system. This philosophy can be used for any number of phases
not shown in Figure 5-20, Clock Phasing Summary.
For example, a 10-phase system could be configured as shown in Figure 5-22.
40 APPLICATION INFORMATION Copyright © 2005–2013, Texas Instruments Incorporated
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