LTC1727/LTC1728
Micropower Precision
Triple Supply Monitors in 8-Lead MSOP
and 5-Lead SOT-23 Packages
FEATURES DESCRIPTION
n
Monitors Three Inputs Simultaneously The LTC 1727 is a triple supply monitor intended for
LTC1727-5: 5V, 3.3V and ADJ systems with multiple supply voltages. Each supply moni-
LTC1727-2.5: 2.5V, 3.3V and ADJ tor has its own open-drain output for individual supply
LTC1728-5: 5V, 3.3V and ADJ monitoring. A common open-drain reset output remains
LTC1728-2.5: 2.5V, 3.3V and ADJ low until all three supplies have been in compliance for
LTC1728-1.8: 3V, 1.8V and ADJ 200ms. Tight 1.5% accuracy specifications and glitch
LTC1728-3.3: 3.3V, 1.8V and ADJ immunity ensure reliable reset operation without false
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1.5% Threshold Accuracy Over Temperature triggering.
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Very Low Supply Current: 10A Typ
The LTC1728 is functionally identical to the LTC1727
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200ms Reset Time Delay
without the individual monitor outputs.
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Active Low RESET Output
n The RST output is guaranteed to be in the correct state
Power Supply Glitch Immunity
n for V /V /V or V down to 1V. The LTC1727/
Guaranteed RESET for V 1V CC5 CC25 CC18 CC3
CC3
LTC1728 may also be configured to monitor any one or
or V /V /V 1V
CC5 CC25 CC18
n two V inputs instead of three, depending on system
LTC1727 Includes Monitor Output for Each Supply CC
n requirements.
LTC1727: 8-Lead MSOP and SO Packages
n
LTC1728: 5-Lead SOT-23 Package
Very low (10A typical) supply current makes the LTC1727/
LTC1728 ideal for power conscious systems.
APPLICATIONS
The LTC1727 is available in an 8-lead MSOP or SO pack-
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Desktop Computers age and the LTC1728 is available in a 5-lead SOT-23
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Notebook Computers package.
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Intelligent Instruments
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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Portable Battery-Powered Equipment
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Network Servers
TYPICAL APPLICATION
3.3V
Triple Supply Monitor with Power Good Output
DC/DC 5V SYSTEM
CONVERTER LOGIC
1.8V (3.3V, 2.5V and Adjustable)
LTC1727-2.5
10k 10k
V RST
CC3
POWER
3.3V V COMP3
CC3
GOOD
LTC1728-5
2.5V V COMP25
CC25
V
CC5
R1
0.1F ADJUSTABLE SYSTEM
61.9k
V RST
CCA
SUPPLY RESET
1%
0.1F
V GND
CCA
R2
GND COMPA
100k
1727/28 TA08
1727/28 TA01
1%
17278fd
1
For more information www.linear.com/LTC1727LTC1727/LTC1728
ABSOLUTE MAXIMUM RATINGS (Notes 1, 2)
V , V /V /V , V 0.3V to 7V Operating Temperature Range
CC3 CC5 CC25 CC18 CCA ........................
RST ............................................................. 0.3V to 7V LTC1727/LTC1728E (Note 3) ............... 40C to 85C
COMPA, COMP3, COMP25/COMP5 LTC1728H .......................................... 40C to 125C
(MS8 and SO-8 Only) ............................. 0.3V to 7V LTC1727I.............................................. 40C to 85C
Storage Temperature Range .................. 65C to 150C
Lead Temperature (Soldering, 10 sec) .................. 300C
PIN CONFIGURATION
TOP VIEW
V 1 8 COMP3 TOP VIEW
CC3
TOP VIEW
V / COMP25/
CC5
2 7
RST 1 5 V
V COMP5 CC3
V 1 8 COMP3 CC25
CC3
V /V 2 7 COMP25/COMP5 V 3 6 RST
CCA GND 2
CC5 CC25
V /
CC5
V 3 6 RST
CCA
V 3 4 V /
GND 4 5 COMPA CC25
CCA
GND 4 5 COMPA
V
CC18
MS8 PACKAGE S8 PACKAGE S5 PACKAGE
8-LEAD PLASTIC MSOP 8-LEAD PLASTIC SO 5-LEAD PLASTIC SOT-23
T = 125C, = 200C/W T = 125C, = 150C/W T = 125C, = 250C/W
JMAX JA JMAX JA JMAX JA
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC1727EMS8-2.5#PBF LTC1727EMS8-2.5#TRPBF LTHY 8-Lead Plastic MSOP 40C to 85C
LTC1727EMS8-2.5#PBF LTC1727EMS8-2.5#TRPBF LTHX 8-Lead Plastic MSOP 40C to 85C
LTC1727ES8-2.5#PBF LTC1727ES8-2.5#TRPBF 172725 8-Lead Plastic SO 40C to 85C
LTC1727IS8-2.5#PBF LTC1727IS8-2.5#TRPBF 727I25 8-Lead Plastic SO 40C to 85C
LTC1727ES8-5#PBF LTC1727ES8-5#TRPBF 17275 8-Lead Plastic SO 40C to 85C
LTC1727IS8-5#PBF LTC1727IS8-5#TRPBF 172715 8-Lead Plastic SO 40C to 85C
LTC1728ES5-1.8#PBF LTC1728ES5-1.8#TRPBF LTPH 8-Lead Plastic SOT-23 40C to 85C
LTC1728ES5-2.5#PBF LTC1728ES5-2.5#TRPBF LTIA 8-Lead Plastic SOT-23 40C to 85C
LTC1728ES5-3.3#PBF LTC1728ES5-3.3#TRPBF LTYP 8-Lead Plastic SOT-23 40C to 85C
LTC1728ES5-5#PBF LTC1728ES5-5#TRPBF LTHZ 8-Lead Plastic SOT-23 40C to 85C
LTC1728HS5-5#PBF LTC1728HS5-5#TRPBF LTHZ 8-Lead Plastic SOT-23 40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: