LTC3883/LTC3883-1
Single Phase Step-Down
DC/DC Controller with Digital
Power System Management
DescripTion
FeaTures
2
The LTC®3883/LTC3883-1 are PolyPhase capable DC/DC
synchronous step-down switching regulator controllers
with a PMBus compliant serial interface. The controllers
use a constant frequency, current mode architecture that
is supported by the LTPowerPlay™ software development
tool with graphical user interface (GUI).
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PMBus/I C Compliant Serial Interface
– Telemetry Read-Back Includes V , I , V , I
,
IN IN OUT OUT
Temperature and Faults
– Programmable Voltage, Current Limit, Digital
Soft-Start/Stop, Sequencing, Margining, OV/UV/OC
and Frequency Synchronization (250kHz to 1MHz)
0ꢀ5ꢁ Output Voltage Accuracy over Temperature
Integrated 16-Bit ADC and 12-Bit DAC
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Switching frequency, output voltage, and device address
canbeprogrammedusingexternalconfigurationresistors.
Additionally, parameterscanbesetviathedigitalinterface
or stored in on-chip EEPROM.
Integrated High Side Current Sense Amplifier
Internal EEPROM and Fault Logging
Integrated N-Channel MOSFET Gate Drivers
The LTC3883/LTC3883-1 can be configured for Burst
Mode® operation,discontinuous(pulse-skipping)modeor
continuousinductorcurrentmode.TheLTC3883incorpo-
rates an internal 5V linear regulator while the LTC3883-1
uses an external 5V supply for minimum power loss.
Power Conversion
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Wide V Range: 4.5V to 24V
IN
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V
Range: 0.5V to 5.5V
OUT
Analog Current Mode Control Loop
Accurate PolyPhase® Current Sharing for
Up to 6 Phases
The LTC3883/LTC3883-1 are available in a 32-lead 5mm
× 5mm QFN package.
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Auto Calibration of Inductor DCR
Available in a 32-Lead (5mm × 5mm) QFN Package
L, LT, LTC, LTM, OPTI-LOOP, PolyPhase, Burst Mode, µModule, Linear Technology and
the Linear logo are registered trademarks and LTpowerPlay, No R
and UltraFast are
SENSE
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6100678,
6144194, 6177787, 5408150, 6580258, 6304066, 7420359, Patent Pending.
applicaTions
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High Current Distributed Power Systems
Telecom Systems
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Intelligent Energy Efficient Power Regulation
Typical applicaTion
5mΩ
V
IN
6V TO 24V
Efficiency and Power Loss
vs Load Current
10µF
1µF
10µF
D1
INTV
CC
100Ω
1µF
100Ω
100
90
80
70
60
50
40
30
20
10
0
8
7
6
5
4
3
2
1
0
TG
M1
M2
V
V
f
= 12V
0.1µF
IN
OUT
= 350kHz
= 1.8V
I
BOOST
SW
IN_SNS
0.56µH
V
1.8V
20A
SW
OUT
V
V
IN_SNS
IN
1.4k
0.22µF
BG
22µF
LTC3883*
+
–
I
I
SDA
SCL
SENSE
SENSE
PMBus
ALERT
RUN
INTERFACE
V
SENSE
TSNS
C
OUT
530µF
10nF
1µF
MMBT3906
2200pF
4.99k
FAULT
GPIO
I
TH
MANAGEMENT
PGOOD
0.01
0.1
1
10
100
V
V
DD33
DD25
LOAD CURRENT (A)
TO/FROM
*SOME DETAILS OMITTED
FOR CLARITY
SHARE_CLK
WP
1µF
OTHER LTC DEVICES
WRITE PROTECT
3883 TA01b
SGND
3883 TA01a
3883f
1