LTC2938/LTC2939
Con gurable 4- and 6-Supply
Monitors with Watchdog Timer
FEATURES DESCRIPTION
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Simultaneously Monitors Four (LTC2938) or Six
The LTC 2938/LTC2939 are con gurable supply monitors
Supplies (LTC2939)
for systems with up to four or six supply voltages that need
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Sixteen User-Selectable Combinations of 5V, 3.3V,
watchdog supervision. One of sixteen preset or adjustable
2.5V, 1.8V, 1.5V, 1.2V and/or Adjustable Voltage
voltage monitor combinations can be selected using an
Thresholds
external resistive divider connected to the program input.
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Guaranteed Threshold Accuracy: 1.5%
The preset voltage thresholds are accurate to 1.5% over
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Adjustable Reset and Watchdog Timeout
temperature. The LTC2938 and LTC2939 also feature ad-
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Low Supply Current: 80A Typical
justable inputs with a 0.5V nominal threshold.
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Power Supply Glitch Immunity
The reset and watchdog timeout periods are adjustable
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Guaranteed RST for V > 1V
CC
using external capacitors. Tight voltage threshold accuracy
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High Temperature Operation to 125C
and glitch immunity ensure reliable reset operation without
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12-Pin 4mm 3mm DFN or 12-Lead MSOP
false triggering. The RST output is guaranteed to be in the
(LTC2938) and 16-Lead MSOP Package (LTC2939)
correct state for V down to 1V. Each status output has
CC
a weak internal pull-up and may be externally pulled up
APPLICATIONS
to a user-de ned voltage.
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Desktop and Notebook Computers
The 80A supply current makes the LTC2938 and LTC2939
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Multivoltage Systems
ideal for power conscious systems. The LTC2939 moni-
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Telecom Equipment
tors up to six supplies and the LTC2938 monitors up to
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Network Servers
four supplies.
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Automotive Control Systems
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 6967591, 7239251, 7119714.
TYPICAL APPLICATION
6-Supply Monitor 12V (ADJ), 5V, 3.3V, 2.5V, 1.8V, 1.2V (ADJ) Voltage Con guration Table
12V
V1 (V) V2 (V) V3 (V) V4 (V) V5 (V) V6 (V)
5V
5 3.3 2.5 1.8 ADJ ADJ
3.3V
SYSTEM
2.5V 5 3.3 2.5 ADJ ADJ ADJ
LOGIC
1.8V
5 3.3 1.8 ADJ ADJ ADJ
1.2V
5 3.3 ADJ ADJ ADJ ADJ
2150k 124k
5 3.3 ADJ ADJ ADJ ADJ
1% 1%
3.3 2.5 1.8 1.5 ADJ ADJ
V1
V2
3.3 2.5 1.8 ADJ ADJ ADJ
V3
3.3 1.8 1.5 1.2 ADJ ADJ
V4 WDI
0.1F
V5
3.3 1.8 1.5 ADJ ADJ ADJ
LTC2939
V6 WDO
0.1F 3.3 1.8 1.2 ADJ ADJ ADJ
V
REF
100k 100k
RST
R1
3.3 2.5 ADJ ADJ ADJ ADJ
1% 1%
59k
3.3 2.5 ADJ ADJ ADJ ADJ
1%
V
PG t = 94ms
RST
3.3 1.8 ADJ ADJ ADJ ADJ
GND CWT CRT t = 940ms
WD
R2
3.3 1.8 ADJ ADJ ADJ ADJ
C C
40.2k WT RT
3.3 1.5 ADJ ADJ ADJ ADJ
47nF 47nF
1%
293839 TA01 3.3 1.2 ADJ ADJ ADJ ADJ
293839ff
1LTC2938/LTC2939
ABSOLUTE MAXIMUM RATINGS (Notes 1, 2, 3)
V1, V2, V3, V4, V5, V6, V ......................... 0.3V to 7V Operating Temperature Range
PG
RST .............................................................. 0.3V to 7V LTC2939C ..................................................... 0C to 70C
CWT, WDO .................................................... 0.3V to 7V LTC2939I .................................................. 40C to 85C
CRT, V , WDI ..............................0.3V to (V + 0.3V) LTC2939H .............................................. 40C to 125C
REF CC
Reference Load Current (I ) .............................. 1mA Storage Temperature Range ................... 65C to 150C
VREF
V4 Input Current (ADJ Mode) ..............................1mA Lead Temperature (Soldering 10 sec)
RST, WDO Currents ............................................10mA MS Package Only .............................................. 300C
PIN CONFIGURATION
LTC2938 LTC2938 LTC2939
TOP VIEW
V3 1 12 V2 TOP VIEW TOP VIEW
V5 1 16 V6
V1 2 11 V4
V3 1 12 V2
V3 2 15 V2
V1 2 11 V4
CRT 3 10 V V1 3 14 V4
REF
13 CRT 3 10 V NC 4 13 NC
REF
RST 4 9 V
PG 4 CRT 5 12 V
RST 9 V REF
PG
RST 6 11 V
5 PG
WDO 8 GND
WDO 5 8 GND
WDO 7 10 GND
6 7 CWT
WDI
WDI 8 9 CWT
WDI 6 7 CWT
MS PACKAGE MS PACKAGE
12-LEAD PLASTIC MSOP 16-LEAD PLASTIC MSOP
DE PACKAGE
12-LEAD (4mm s 3mm) PLASTIC DFN
T = 125C, = 130C/W T = 125C, = 110C/W
JMAX JA JMAX JA
T = 125C, = 43C/W
JMAX JA
EXPOSED PAD (PIN 13) PCB GND CONNECTION OPTIONAL
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC2938CDE#PBF LTC2938CDE#TRPBF 2938 0C to 70C
12-Lead (4mm 3mm) Plastic DFN
LTC2938IDE#PBF LTC2938IDE#TRPBF 2938 40C to 85C
12-Lead (4mm 3mm) Plastic DFN
LTC2938HDE#PBF LTC2938HDE#TRPBF 2938 12-Lead (4mm 3mm) Plastic DFN 40C to 125C
LTC2938CMS#PBF LTC2938CMS#TRPBF 2938 12-Lead Plastic MSOP 0C to 70C
LTC2938IMS#PBF LTC2938IMS#TRPBF 2938 12-Lead Plastic MSOP 40C to 85C
LTC2938HMS#PBF LTC2938HMS#TRPBF 2938 12-Lead Plastic MSOP 40C to 125C
LTC2939CMS#PBF LTC2939CMS#TRPBF 2939 16-Lead Plastic MSOP 0C to 70C
LTC2939IMS#PBF LTC2939IMS#TRPBF 2939 16-Lead Plastic MSOP 40C to 85C
LTC2939HMS#PBF LTC2939HMS#TRPBF 2939 16-Lead Plastic MSOP 40C to 125C
Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container.
For more information on lead free part marking, go to: