Datasheet

Example 2: Cascading Configuration: 24 V to 12 V at 2 A then 3.3 V at 2 A
U
0 1.00.5 2.01.5 2.5
I
LOAD
– Load Current – A
10
0
30
20
100
h – Efficiency – %
V
OUT
= 3.3 V
3.3
12
V
OUT
(V)
V
OUT
= 12 V
60
50
80
70
40
90
TPS55383 , , TPS55386
www.ti.com ......................................................................................................................................................................................... SLUS818 – SEPTEMBER 2008
This example illustrates a cascaded configuration. To accommodate the low duty cycle of a 24-V to 3.3-V supply,
PVDD1 is connected to VOUT2, a 12-V output. VOUT2 is used as the source supply for VOUT1. The sequence
pin is connected to BP, ensuring the 12-V supply is in regulation before the 3.3-V is allowed to turn on.
Figure 36. Design Example 2, TPS55386 in a Cascaded Configuration
EFFICIENCY
vs
LOAD CURRENT
Figure 37. Figure 38. Design Example 2 Outputs and Switch Nodes
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