Datasheet

V
O
V
I
INH/UVLO
-Sense
GND
GND
Track SYNC TT
VoAdj
C 2
330 F
I
m
C 2
200 F
O
m
R 2
SET
V =5V
I
V 1
O
V 2
O
PTH08T240W
V
CC
GND
f =2xf
clock modules
CLK
CLR
SN74LVC2G74
0
o
PRE
D
Q
Q
180
o
+Sense
GND
C 1
200 F
O
m
R 1
SET
C 1
330 F
I
m
V
O
V
I
INH/UVLO
-Sense
GND
Track SYNC TT
VoAdj
PTH08T230W
+Sense
PTH08T230W, PTH08T231W
SLTS265L –NOVEMBER 2005– REVISED AUGUST 2011 www.ti.com
Smart Sync
Smart Sync is a feature that allows multiple power modules to be synchronized to a common frequency. Driving
the Smart Sync pins with an external oscillator set to the desired frequency, synchronizes all connected modules
to the selected frequency. The synchronization frequency can be higher or lower than the nominal switching
frequency of the modules within the range of 240 kHz to 400 kHz (see Electrical Specifications table for
frequency limits). Synchronizing modules powered from the same bus, eliminates beat frequencies reflected back
to the input supply, and also reduces EMI filtering requirements. These are the benefits of Smart Sync. Power
modules can also be synchronized out of phase to minimize source current loading and minimize input
capacitance requirements. Figure 24 shows a standard circuit with two modules syncronized 180° out of phase
using a D flip-flop.
Figure 24. Typical SmartSync Circuit
26 Copyright © 2005–2011, Texas Instruments Incorporated