Datasheet

PWM1 0°

PWM2 180°

SYNC

PWM1 90°

PWM2 270°

PWM1

PWM2

TPS40322

Master

TPS40322

Slave

PWM1

PWM2

PHSET

PHSETBP6

UDG-11117

20 10

TPS40322

SLUSAF8D –JUNE 2011–REVISED JANUARY 2014

www.ti.com

Shutdown

During the shutdown sequence, BP6 is controlled by ENx/SSx. If both of ENx/SSx pins are pulled low, BP6 is

turned off regardless of the input voltage remaining higher than the programmed UVLO threshold.

Switching Frequency and Master/Slave Synchronization

The switching frequency is set by the value of the resistor connected from the RT pin to AGND. The RT resistor

value is calculated in Equation 5.

where

• R

is the the resistor from RT pin to AGND, in Ω

• f

is the desired switching frequency, in Hz (5)

The TPS40322 device can also synchronize to an external clock that is ±20% of the master clock frequency

which is two times the free running frequency. Each TPS40322 can be set by the PHSET pin as either master or

slave. The master produces a 50% duty cycle clock to the slave. The slave synchronizes to the external clock

with 50% duty cycle and selects the phase shift angle as shown in Table 2.

Figure 21 shows an example on synchronizing two TPS40322 devices to generate an evenly distributed shift to

reduce input ripple.

Table 2. Phase Shift Angle Selection

PHSET MODE PHASE ANGLE (°)

RANGE

CONNECTION CH1 CH2

(V)

AGND < 0.5 Master 0 180

Floating 0.6 to 2 Slave 0 180

High > 2.1 Slave 90 270

XXXX

Figure 21. Synchronizing Two TPS40322 Devices