LTC1727_15 Datasheet, PDF (1/16 Pages) Linear Technology – Micropower Precision Triple Supply Monitors in 8-Lead MSOP and 5-Lead SOT-23 Packages

Features
n _{Monitors Three Inputs Simultaneously}
LTC1727-5: 5V, 3.3V and ADJ
LTC1727-2.5: 2.5V, 3.3V and ADJ
LTC1728-5: 5V, 3.3V and ADJ
LTC1728-2.5: 2.5V, 3.3V and ADJ
LTC1728-1.8: 3V, 1.8V and ADJ
LTC1728-3.3: 3.3V, 1.8V and ADJ
n _{±1.5% Threshold Accuracy Over Temperature}
n _{Very Low Supply Current: 10µA Typ}
n _{200ms Reset Time Delay}
n _{Active Low RESET Output}
n _{Power Supply Glitch Immunity}
n _{Guaranteed RESET for VCC3 ≥ 1V}
or V_CC5/V_CC25/V_CC18 ≥ 1V
n _{LTC1727 Includes Monitor Output for Each Supply}
n _{LTC1727: 8-Lead MSOP and SO Packages}
n _{LTC1728: 5-Lead SOT-23 Package}
Applications
n _{Desktop Computers}
n _{Notebook Computers}
n _{Intelligent Instruments}
n _{Portable Battery-Powered Equipment}
n _{Network Servers}
LTC1727/LTC1728
Micropower Precision
Triple Supply Monitors
in 8-Lead MSOP and
5-Lead SOT-23 Packages
Description
The LTC^®1727 is a triple supply monitor intended for
systems with multiple supply voltages. Each supply moni-
tor has its own open-drain output for individual supply
monitoring. A common open-drain reset output remains
low until all three supplies have been in compliance for
200ms. Tight 1.5% accuracy specifications and glitch
immunity ensure reliable reset operation without false
triggering.
The LTC1728 is functionally identical to the LTC1727
without the individual monitor outputs.
The RST output is guaranteed to be in the correct state
for V_CC5/V_CC25/V_CC18 or V_CC3 down to 1V. The LTC1727/
LTC1728 may also be configured to monitor any one or
two V_CC inputs instead of three, depending on system
requirements.
Very low (10µA typical) supply current makes the LTC1727/
LTC1728 ideal for power conscious systems.
The LTC1727 is available in an 8-lead MSOP or SO pack-
age and the LTC1728 is available in a 5-lead SOT-23
package.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Typical Application
3.3V
DC/DC 5V
CONVERTER _1.8V
SYSTEM
LOGIC
0.1µF
0.1µF
5
4
R1
61.9k
1% 3
R2
100k
1%
V_CC3
1
RST
LTC1728-5
V_CC5
V_CCA
2
GND
1727/28 TA01
Triple Supply Monitor with Power Good Output
(3.3V, 2.5V and Adjustable)
ADJUSTABLE
SUPPLY
3.3V
2.5V
R1
R2
LTC1727-2.5
R3
1 _{VCC3 COMP3} 8
10k
2 _{VCC25 COMP25} 7
3 _VCCA
RST ⁶
4 _GND
COMPA 5
1727/28 TA08
R4
10k
POWER
GOOD
SYSTEM
RESET
17278fb
1