LTC2904/LTC2905
Precision Dual Supply
Monitors with Pin-Selectable
Thresholds
FEATURES DESCRIPTION
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Monitors Two Inputs Simultaneously The LTC 2904/LTC2905 are dual supply monitors in-
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Nine Threshold Combinations tended for systems with two supply voltages. The dual
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Three Supply Tolerances (5%, 7.5%, 10%) supply monitors have a common reset output with delay
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Guaranteed Threshold Accuracy: 1.5% of (200ms for the LTC2904 and adjustable using an exter-
Monitored Voltage Over Temperature nal capacitor for the LTC2905). This product provides a
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Internal V Auto Select precise, space-conscious and micropower solution for
CC
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Power Supply Glitch Immunity supply monitoring.
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200ms Reset Time Delay (LTC2904 Only)
The LTC2904/LTC2905 feature a tight 1.5% threshold
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Adjustable Reset Time Delay (LTC2905 Only)
accuracy over the whole operating temperature range, and
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Open Drain RST Output
glitch immunity to ensure reliable reset operation without
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Guaranteed RST for V1 1V or V2 1V
false triggering. The open drain RST output is guaranteed
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Low Pro le (1mm) SOT-23 (ThinSOT) and
to be in the correct state for inputs down to 1V.
Plastic (3mm 2mm) DFN Packages
The LTC2904/LTC2905 also feature three programming
input pins, which program the threshold and tolerance level
APPLICATIONS
without requiring any external components. These three
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Desktop and Notebook Computers programming pins provide a total of 27 different voltage
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Handheld Devices level and tolerance combinations, eliminating the need to
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Network Servers have different parts for development and implementation
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Core, I/O Monitor of different systems with different voltage levels requiring
monitoring function.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V, 3.3V Dual Supply Monitor with 5% Tolerance
Table 1. Voltage Threshold Programming
V1 V2 S1 S2
5V
DC/DC
SYSTEM
3.3V
CONVERTER 5.0 3.3 V1 V1
LOGIC
3.3 2.5 Open GND
V1 V2
3.3 1.8 V1 Open
LTC2905
0.1F 0.1F
3.3 1.5 Open V1
S1 TMR
3.3 1.2 Open Open
22nF
S2 GND 2.5 1.8 GND GND
2.5 1.5 GND Open
TOL RST
29045 TA01
2.5 1.2 GND V1
2.5 1.0 V1 GND
29045fd
1LTC2904/LTC2905
ABSOLUTE MAXIMUM RATINGS (Note 1, 2)
Terminal Voltages Operating Temperature Range
V1, V2 ...................................................... 0.3V to 7V LTC2904C/LTC2905C .............................. 0C to 70C
S1, S2, TOL ................................0.3V to (V +0.3V) LTC2904I/LTC2905I .............................40C to 85C
CC
RST .......................................................... 0.3V to 7V LTC2905H .......................................... 40C to 125C
RST (LTC2904) ........................................ 0.3V to 7V Storage Temperature Range .................. 65C to 150C
TMR (LTC2905) ....................................... 0.3V to 7V TSOT Lead Temperature (Soldering, 10 sec) .........300C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
GND 1 8 TOL
V2 1 8 V1
RST 2 7 S1
9
RST/TMR* 2 7 S2
RST/TMR* S2
3 6
RST 3 6 S1
V2 4 5 V1
GND 4 5 TOL
TS8 PACKAGE
DDB8 PACKAGE
8-LEAD PLASTIC TSOT-23
8-LEAD (3mm s 2mm) PLASTIC DFN
* RST FOR LTC2904
EXPOSED PAD IS GND (PIN 9),
TMR FOR LTC2905
MUST BE SOLDERED TO PCB
T = 150C, = 195C/W
JMAX JA
* RST FOR LTC2904
TMR FOR LTC2905
= 150C, = 76C/W
T
JMAX JA
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC2904CDDB#TRMPBF LTC2904CDDB#TRPBF LBCZ 8-Lead (3mm 2mm) Plastic DFN 0C to 70C
LTC2904IDDB#TRMPBF LTC2904IDDB#TRPBF LBDB 8-Lead (3mm 2mm) Plastic DFN 40C to 85C
LTC2905CDDB#TRMPBF LTC2905CDDB#TRPBF LAJF 8-Lead (3mm 2mm) Plastic DFN 0C to 70C
LTC2905HDDB#TRMPBF LTC2905HDDB#TRPBF LBCY 40C to 125C
8-Lead (3mm 2mm) Plastic DFN
LTC2905IDDB#TRMPBF LTC2905IDDB#TRPBF LBCY 8-Lead (3mm 2mm) Plastic DFN 40C to 85C
LTC2904CTS8#TRMPBF LTC2904CTS8#TRPBF LTBCJ 8-Lead Plastic TSOT-23 0C to 70C
LTC2904ITS8#TRMPBF LTC2904ITS8#TRPBF LTBCK 8-Lead Plastic TSOT-23 40C to 85C
LTC2905CTS8#TRMPBF LTC2905CTS8#TRPBF LTAJD 8-Lead Plastic TSOT-23 0C to 70C
LTC2905HTS8#TRMPBF LTC2905HTS8#TRPBF LTAJE 8-Lead Plastic TSOT-23 40C to 125C
LTC2905ITS8#TRMPBF LTC2905ITS8#TRPBF LTAJE 8-Lead Plastic TSOT-23 40C to 85C
TRM = 500 pieces. *Temperature grades are identi ed by a label on the shipping container.
Consult LTC Marketing for parts speci ed with wider operating temperature ranges.
Consult LTC Marketing for information on lead based nish parts.
For more information on lead free part marking, go to: