LTC3883 Datasheet, PDF (1/112 Pages) Linear Technology – Single Phase Step-Down DC/DC Controller with Digital Power System Management

LTC3883/LTC3883-1
Single Phase Step-Down
DC/DC Controller with Digital
Power System Management
Features
Description
n _PMBus/I²_{C Compliant Serial Interface}
– Telemetry Read-Back Includes V_IN, I_IN, V_OUT, I_OUT,
Temperature and Faults
– Programmable Voltage, Current Limit, Digital
Soft-Start/Stop, Sequencing, Margining, OV/UV/OC
and Frequency Synchronization (250kHz to 1MHz)
n _{±0.5% Output Voltage Accuracy over Temperature}
n _{Integrated 16-Bit ADC and 12-Bit DAC}
n _{Integrated High Side Current Sense Amplifier}
n _{Internal EEPROM and Fault Logging}
n _{Integrated N-Channel MOSFET Gate Drivers}
Power Conversion
n _{Wide VIN Range: 4.5V to 24V}
n _{VOUT Range: 0.5V to 5.5V}
n _{Analog Current Mode Control Loop}
n _{Accurate PolyPhase}^® _{Current Sharing for}
Up to 6 Phases
n _{Auto Calibration of Inductor DCR}
n _{Available in a 32-Lead (5mm × 5mm) QFN Package}
Applications
n _{High Current Distributed Power Systems}
n _{Telecom Systems}
n _{Intelligent Energy Efficient Power Regulation}
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).
Switching frequency, output voltage, and device address
can be programmed using external configuration resistors.
Additionally, parameters can be set via the digital interface
or stored in on-chip EEPROM.
The LTC3883/LTC3883-1 can be configured for Burst
Mode^® operation, discontinuous (pulse-skipping) mode or
continuous inductor current mode. The LTC3883 incorpo-
rates an internal 5V linear regulator while the LTC3883-1
uses an external 5V supply for minimum power loss.
The LTC3883/LTC3883-1 are 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_SENSE and UltraFast are
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.
Typical Application
V_IN
6V TO 24V
5mΩ
100Ω
1µF
100Ω
22µF
PMBus
INTERFACE
FAULT
MANAGEMENT
TO/FROM
OTHER LTC DEVICES
WRITE PROTECT
10µF
INTV_CC
10µF
1µF
D1
TG
M1
0.1µF
I_{IN_SNS} BOOST
V_{IN_SNS}
SW
V_IN
BG
LTC3883*
0.56µH
M2 1.4k
0.22µF
V_OUT
1.8V
20A
SDA
SCL
ALERT
RUN
I_SENSE+
I_SENSE–
V_SENSE
TSNS
GPIO
PGOOD
2200pF
4.99k
I_TH
V_DD33
V_DD25
SHARE_CLK
1µF
WP
SGND
10nF _MMBT3906
C_OUT
530µF
1µF
*SOME DETAILS OMITTED
FOR CLARITY
3883 TA01a
Efficiency and Power Loss
vs Load Current
100
90
V_IN = 12V
V_OUT = 1.8V
80 ^{fSW = 350kHz}
70
60
50
40
30
20
10
0
0.01
0.1
1
10
LOAD CURRENT (A)
8
7
6
5
4
3
2
1
0
100
3883 TA01b
3883f
1