LTC2911
Precision Triple Supply
Monitor with Power-Fail
Comparator
FEATURES
DESCRIPTION
The LTC®2911 is a low power, high accuracy triple supply
monitor with a power-fail comparator. Reset timeout may
beselectedwithanexternalcapacitororsettoaninternally
generated 200ms.
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Ultralow Voltage Reset: V = 0.5V Guaranteed
Monitors Three Inputs Simultaneously:
CC
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3.3V, 5V, ADJ (LTC2911-1)
3.3V, 2.5V, ADJ (LTC2911-2)
3.3V, 1.8V, ADJ (LTC2911-3)
3.3V, 1.2V, ADJ (LTC2911-4)
3.3V, ADJ, ADJ (LTC2911-5)
The V1 pin monitors a 3.3V supply. The V2 pin monitors a
5V, 2.5V, 1.8V, 1.2V or adjustable supply. A third adjustable
input has a nominal 0.5V threshold allowing a resistive
divider to configure its threshold. All three comparators
feature a tight 1.5% threshold accuracy over the entire
operating temperature range while a glitch filter ensures
reliable reset operation.
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1.5ꢀ Threshold Aꢁꢁuraꢁy
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Power-Fail Monitor
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RST State Can Be Held for Margining
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Low Supply Current: 30µA Typical
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Input Glitch Immunity
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A spare comparator can be configured to provide early
warningofalowvoltagecondition.ItcausesthePFOoutput
topulllowwhenthevoltageofthePFIinputfallsbelow0.5V,
allowing the power-fail threshold to be configured with
a resistive divider. A latch feature on the TMR pin allows
the RST output to be latched to prevent system resets,
simplifying margin testing.
Adjustable Reset Timeout Period
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Selectable Internal Timeout Saves Components
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Space Saving 8-Lead TSOT-23 and 3mm × 2mm DFN
Packages
APPLICATIONS
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L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6949965, 7292076.
Network Servers
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Desktop and Notebook Computers
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Automotive and Industrial Electronics
TYPICAL APPLICATION
RST Output Voltage With 10k Pull-Up to V1
3.3V
6
V1 = V2
2.5V
1.0V
DC/DC
SYSTEM
LOGIC
CONVERTER
5
4
3
2
1
0
10k
TMR
V1
RESET
LOBAT
RST
PFO
V2
76.8k
100k
LTC2911-2
ADJ
576k
Li-Ion
BATTERY
STACK
+
PFI
GND
100k
t
= 200ms
RST
2911 TA01a
0
0.5
1
1.5
2
2.5
3 3.5 4 4.5 5 5.5
V1 (V)
2911 TA01b
2911f
1