Datasheet

4 5 6 7 3 2 1
EP
VOUT
FB RON SS
VIN
EN GND
V
IN
C
IN
2
10 PF
Enable
4.5V to 20V
C
FF
0.022 PF
U1
C
SS
0.022 PF
R
FBB
1.07k
LMZ12001EXTTZ-ADJ
1.8V
O
@ 1A
C
O
1
1 PF
C
O
2
100 PF
R
ON
32.4k
R
ENT
32.4k
R
ENB
11.8k
R
FBT
1.37k
C
IN
1
1 PF
D1
OPT
LMZ12001EXT
SNVS661F –JUNE 2010–REVISED OCTOBER 2013 www.ti.com
ZERO COIL CURRENT DETECTION
The current of the lower (synchronous) MOSFET is monitored by a zero coil current detection circuit which
inhibits the synchronous MOSFET when its current reaches zero until the next on-time. This circuit enables the
DCM operating mode, which improves efficiency at light loads.
PRE-BIASED STARTUP
The LMZ12001EXT will properly start up into a pre-biased output. This startup situation is common in multiple rail
logic applications where current paths may exist between different power rails during the startup sequence. The
following scope capture shows proper behavior during this event.
Figure 42. Pre-Biased Startup
Evaluation Board Schematic Diagram and BOM
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