L6732

Device description

19/37

other one will be the slave. The Slave controller will increase its switching frequency

reducing the ramp amplitude proportionally and then the modulator gain will be increased.

To avoid a huge variation of the modulator gain, the best way to synchronize two or more

devices is to make them work at the same switching frequency and, in any case, the

switching frequencies can differ for a maximum of 50 % of the lowest one. If, during

synchronization between two (or more) L6732, it's important to know in advance which the

master is, it's timely to set its switching frequency at least 15 % higher than the slave. Using

Equation 5

The phase shift between master and slaves is approximately 180 °.

Figure 13.

Synchronization: PWM signal

Figure 14.

Synchronization: Inductor currents

SW

EXT

SW

f

f

f

⋅

≤

≤

3

,

1