Datasheet

6
SS
S0204-01
Shutdown
TPS40077
6
6
4
4
SS
SS
ToSystemPowerGood
PGD
PGD
S0205-01
TPS40077
TPS40077
BOOST AND LVBP BYPASS CAPACITANCE
TPS40077
SLUS714D – JANUARY 2007 – REVISED APRIL 2009 ..................................................................................................................................................... www.ti.com
Figure 26. TPS40077 Shutdown
In a similar manner, power supplies based on the TPS40077 can be sequenced by connecting the PGD pin of
the first supply to come up to the SS pin of the second supply as shown in Figure 27 .
Figure 27. TPS40077 Sequencing
The BOOST capacitance provides a local, low-impedance flying source for the high-side driver. The BOOST
capacitor should be a good-quality, high-frequency capacitor. A capacitor with a minimum value of 100-nF is
suggested.
The LVBP pin must provide energy for both the synchronous MOSFET and the high-side MOSFET (via the
BOOST capacitor). The suggested value for this capacitor is 1- µ F ceramic, minimum.
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