Datasheet

t
BPS
+
4.5 C
BP5
8 10
*3
1.0
0.7
EN
BP5
SS
VOUT
PGOOD
t -Time
BP5
BP5
BP5
1
2
3
4
4-Phase
Operation
1
2
3
4
3-Phase
Operation
2-Phase
Operation
1
2
3
4
TPS40090
TPS40091
www.ti.com SLUS578B –OCTOBER 2003– REVISED MAY 2006
SETTING CONTROLLER CONFIGURATION
By default, the controller operates at four-phase configuration. The alternate number of active phases is
programmed by connecting unused PWM outputs to BP5. (See Figure 1) For example, for three-phase
operation, the unused fourth phase output, PWM4, should be connected to BP5. For two-phase operation, the
second, PWM2, and the fourth, PWM4, outputs should be connected to BP5.
POWER UP
Capacitors connected to the BP5 pin and the soft-start pin set the power-up time. When EN is high, the capacitor
connected to the BP5 pin gets charged by the internal LDO as shown in Figure 2.
(1)
Figure 1. Programming Controller Configuration Figure 2. Power-Up Waveforms
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