Datasheet

LTC3728
36
3728fg
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone]
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FAX: [phone]
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www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2006
LT 0909 REV G • PRINTED IN USA
RELATED PARTS
TYPICAL APPLICATION
PART NUMBER DESCRIPTION COMMENTS
LTC1350 High Power Step-Down Synchronous DC/DC
Controller in SO-8
High Effi ciency 5V to 3.3V Conversion at Up to 15A
LTC1628/LTC1628-PG/
LTC1628-SYNC
2-Phase, Dual Output Synchronous Step-Down
DC/DC Controller
Reduces C
IN
and C
OUT
, Power Good Output Signal, Synchronizable,
3.5V ≤ V
IN
≤ 36V, I
OUT
Up to 20A, 0.8V ≤ V
OUT
≤ 5V
LTC1629/
LTC1629-PG
20A to 200A PolyPhase
®
Synchronous Controllers Expandable from 2-Phase to 12-Phase, Uses All Surface Mount
Components, No Heat Sink, V
IN
Up to 36V
LTC1702
No R
SENSE
™ 2-Phase Dual Synchronous
Step-Down Controller
550kHz, No Sense Resistor
LTC1703 No R
SENSE
2-Phase Dual Synchronous Step-Down
Controller with 5-Bit Mobile VID Control
Mobile Pentium III Processors, 550kHz, V
IN
≤ 7V
LTC1708-PG 2-Phase, Dual Synchronous Controller with
Mobile VID
3.5V ≤ V
IN
≤ 36V, VID Sets V
OUT1
, PGOOD
LT1709/LT1709-8 High Effi ciency, 2-Phase Synchronous Step-Down
Switching Regulators with 5-Bit VID
1.3V ≤ V
OUT
≤ 3.5V, Current Mode Ensures Accurate Current Sharing,
3.5V ≤ V
IN
≤ 36V
LTC1735 High Effi ciency Synchronous Step-Down
Switching Regulator
Output Fault Protection, 16-Pin SSOP
LTC1736 High Effi ciency Synchronous Controller with
5-Bit Mobile VID Control
Output Fault Protection, 24-Pin SSOP, 3.5V ≤ V
IN
≤ 36V
LTC1778 No R
SENSE
Current Mode Synchronous
Step-Down Controller
Up to 97% Effi ciency, 4V ≤ V
IN
≤ 36V, 0.8V ≤ V
OUT
≤ (0.9)(V
IN
),
I
OUT
Up to 20A
LTC1929/LTC1929-PG 2-Phase Synchronous Controllers Up to 42A, Uses All Surface Mount Components, No Heat Sinks,
3.5V ≤ V
IN
≤ 36V
LTC3711 No R
SENSE
Current Mode Synchronous Step-Down
Controller with Digital 5-Bit Interface
Up to 97% Effi ciency, Ideal for Pentium III Processors, 0.925V ≤ V
OUT
≤ 2V,
4V ≤ V
IN
≤ 36V, I
OUT
Up to 20A
LTC3729 20A to 200A, 550kHz PolyPhase Synchronous
Controller
Expandable from 2-Phase to 12-Phase, Uses All Surface Mount
Components, V
IN
Up to 36V
PolyPhase is a registered trademark of Linear Technology Corporation. No R
SENSE
is a trademark of Linear Technology Corporation.
Figure 14. Multioutput PolyPhase Application
PHASMD
CLKOUT
TG1
TG2
0°
I
1
I
3
I
2
I
4
90°
OPEN
180°
U1
LTC3729
BUCK: 2.5V/15A
BUCK: 2.5V/15A
PLLIN
TG1
TG2
90°
90°
270°
U2
LTC3728
BUCK: 1.5V/15A
2.5V
O
/30A
C
IN
I
IN
12V
IN
*INPUT RIPPLE CURRENT CANCELLATION
INCREASES THE RIPPLE FREQUENCY AND
REDUCES THE RMS INPUT RIPPLE CURRENT
THUS, SAVING INPUT CAPACITORS
I
IN
*
1.5V
O
/15A
1.8V
O
/15A
3728 F14
BUCK: 1.8V/15A
I
1
I
2
I
3
I
4