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Easily Configure Power Management
without Software
Controls Up to Four Supplies per Device
Cascades for Additional Supplies
Staged Supply Sequencing with
Adjustable Time Positions
Fault Event Reporting with Diagnostics
Selectable System Shutdown on Fault
1.5% Undervoltage Monitor Accuracy
Overvoltage and/or Fault Indication
Configurable Undervoltage and
Overvoltage Thresholds
Charge Pumped Enable Pins Drive N-Channel
MOSFETs
Operates from 2.9V to 16.5V
5mm
×
7mm 38-lead QFN and
36-lead SSOP Packages
Network/Telecom Infrastructure
Sequencing for Multiple I/O and Core Voltages
Power Management
The LTC
®
2928 is a four channel cascadable power
supply sequencer and high accuracy supervisor. Sequenc-
ing thresholds, order and timing are configured with just a
few external components, negating the need for PC board
layout or software changes during system development.
Multiple LTC2928s may be easily connected to sequence
an unlimited number of power supplies.
Sequence outputs control supply enable pins or
N-channel pass gates. Precision input comparators with
individual outputs monitor power supply voltages to 1.5%
accuracy. Supervisory functions include undervoltage
and overvoltage monitoring and reporting as well as
µP
reset generation.
RST
may be forced high to complement
margin testing.
Application faults, whether internally or externally gener-
ated, can shutdown all controlled supplies. The type and
source of faults are reported for diagnosis. Individual
channel controls are available to independently exercise
enable outputs and supervisory functions.
A high voltage input allows the LTC2928 to be powered
from voltages as high as 16.5V. A buffered reference
output permits single negative power supply sequencing
and monitoring operations.
APPLICATIO S
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, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners. Protected by U.S. Patents
including 4843302, 6949965.
12V
LTM4600
V
IN
V
OUT
RUN
10k
V
IN
LTC3414
V
OUT
LTC1628
V
IN
V
OUT
RUN
AUSTIN LYNX
V
IN
V
OUT
AXA010AY93
0.1 F
ON
95.3k
24.3k
9.53k
1.5k
3.4k
Si7894ADP
HV
CC
EN2
EN1 EN4
1 F
ON
RT1
RT2
RT3
RT4
DONE
V
CC
GND MS1 VSEL
V1
V2
V3
LTC2928
V4
RST
OV
FLT
RTMR PTMR STMR
0.047 F
3300pF
10k
10k
10k
10k
ALL RESISTORS 1%
U
TYPICAL APPLICATIO
3.3V
1.2V
RUN
2.5V
3.3V
2.5V
1.8V
1.2V
1.8V
12.1k
23.2k
36.5k
51.1k
1V/DIV
ON
100
EN3
DONE
SYSTEM
RESET
FAULT
START
SEQUENCE SEQUENCE UP
START
UP COMPLETE
SEQUENCE
DOWN
2928 TA06
U
FEATURES
LTC2928
Multichannel Power Supply
Sequencer and Supervisor
DESCRIPTIO
U
Sequencing Up and Down
SEQUENCE
DOWN
COMPLETE
2928 TA07
2928f
1
LINEAR_DIMENSIONS [ LINEAR DIMENSIONS SEMICONDUCTOR ]
