LTC2931
Con gurable Six Supply
Monitor with Adjustable Reset
and Watchdog Timers
FEATURES DESCRIPTION
Simultaneously Monitors Six Supplies
The LTC 2931 is a con gurable supply monitor for
16 User Selectable Combinations of
systems with up to six supply voltages. One of 16 preset or
5V, 3.3V, 3V, 2.5V, 1.8V, 1.5V and Adjustable
adjustable voltage monitor combinations can be selected
Voltage Thresholds
using an external resistive divider connected to the mode
Guaranteed Threshold Accuracy: 1.5%
select pin. The preset voltage thresholds are accurate
Adjustable Reset and Watchdog Timeout
to 1.5% over temperature. The LTC2931 also features
Low Supply Current: 52A
adjustable inputs with a 0.5V nominal threshold. All six
Comparator/Monitor Output for Each Supply
open-drain voltage comparator outputs are connected to
Power Supply Glitch Immunity
separate pins for individual supply monitoring.
Guaranteed RST for V 1V
CC
The reset and watchdog timeout periods are adjustable
High Temperature Operation to 125C
using external capacitors. Tight voltage threshold accuracy
20-Lead TSSOP Package
and glitch immunity ensure reliable reset operation without
false triggering. The RST output is guaranteed to be in the
APPLICATIONS
correct state for V down to 1V. Each status output has
CC
a weak internal pull-up and may be externally pulled up
Desktop and Notebook Computers
to a user de ned voltage.
Multivoltage Systems
Telecom Equipment The 52A supply current makes the LTC2931 ideal for
Portable Battery-Powered Equipment power conscious systems and it may be con gured to
Network Servers monitor fewer than six inputs.
Automotive L, 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 6967591, 7239251, 7119714.
TYPICAL APPLICATION
Six Supply Monitor 12V (ADJ), 5V, 3.3V, 2.5V, 1.8V, 1.2V (ADJ) Voltage Threshold Con guration Table
12V
V1 (V) V2 (V) V3 (V) V4 (V) V5 (V) V6 (V)
5V
5.0 3.3 2.5 1.8 ADJ ADJ
3.3V
SYSTEM
2.5V LOGIC
5.0 3.3 2.5 1.5 ADJ ADJ
1.8V
5.0 3.3 2.5 ADJ ADJ ADJ
1.2V
5.0 3.3 1.8 ADJ ADJ ADJ
10k
5.0 3.3 1.8 ADJ ADJ ADJ
POWER
2150k 124k
5.0 3.3 ADJ ADJ ADJ ADJ
GOOD
1% 1%
5.0 3.3 ADJ ADJ ADJ ADJ
V1
5.0 3.0 2.5 ADJ ADJ ADJ
V2
V3 5.0 3.0 1.8 ADJ ADJ ADJ
WDI
0.1F
V4 5.0 3.0 ADJ ADJ ADJ ADJ
LTC2931
0.1F
V5
3.3 2.5 1.8 1.5 ADJ ADJ
WDO
V6
3.3 2.5 1.8 ADJ ADJ ADJ
100k 100k
VREF
1% 1%
3.3 2.5 1.8 ADJ ADJ ADJ
R1
RST
59k 2931 TA01
3.3 2.5 1.5 ADJ ADJ ADJ
1%
VPG
t = 94ms
RST
3.3 2.5 ADJ ADJ ADJ ADJ
CWT CRT
GND t = 940ms
WD
R2
3.3 2.5 ADJ ADJ ADJ ADJ
C C
40.2k WT RT
1% 47nF 47nF
2931fb
1
COMP1
COMP2
COMP3
COMP4
COMP5
COMP6LTC2931
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION
(Notes 1, 2, 3)
TOP VIEW
V1, V2, V3, V4, V5, V6, VPG ........................ 0.3V to 7V
COMP5 1 20 COMP6
RST , COMP1-6............................................ 0.3V to 7V
V5 2 19 V6
CWT, WDO .................................................... 0.3V to 7V
COMP3 3 18 COMP2
CRT, VREF, WDI .............................0.3V to (V + 0.3V)
CC
COMP1 4 17 COMP4
Reference Load Current (I ) .............................. 1mA
VREF
V3 5 16 V2
V4 Input Current (ADJ Mode) ..............................1mA
V1 6 15 V4
RST , WDO, COMP1-6 Currents ...........................10mA
CRT 7 14 VREF
Operating Temperature Range
RST 8 13 VPG
LTC2931C ................................................ 0C to 70C
WDO 9 12 GND
LTC2931I.............................................. 40C to 85C WDI 10 11 CWT
LTC2931H .......................................... 40C to 125C
F PACKAGE
20-LEAD PLASTIC TSSOP
Storage Temperature Range ................... 65C to 150C
T = 130C, = 90C/W
JMAX JA
Lead Temperature (Soldering, 10 sec) .................. 300C
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC2931CF#PBF LTC2931CF#TRPBF LTC2931F 20-Lead Plastic TSSOP 0C to 70C
LTC2931IF#PBF LTC2931IF#TRPBF LTC2931F 20-Lead Plastic TSSOP 40C to 85C
LTC2931HF#PBF LTC2931HF#TRPBF LTC2931F 20-Lead Plastic TSSOP 40C to 125C
Consult LTC Marketing for information on non-standard lead based nish parts.
For more information on lead free part marking, go to: