LTC2900
Programmable Quad Supply
Monitor with Adjustable Reset Timer
FEATURES
DESCRIPTIO
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Simultaneously Monitors Four Supplies The LTC 2900 is a programmable supply monitor for
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16 User Selectable Combinations of 5V, 3.3V, 3V, systems with up to four supply voltages. One of 16 preset
2.5V, 1.8V, 1.5V and/or Adjustable Voltage or adjustable voltage monitor combinations can be se-
Thresholds lected using an external resistor divider connected to the
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Guaranteed Threshold Accuracy: 1.5% of program pin. The preset voltage thresholds are accurate
Monitored Voltage Over Temperature to 1.5% over temperature.
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Low Supply Current: 43m A Typ
The reset delay time is adjustable using an external
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Adjustable Reset Time
capacitor and the manual reset input may be used with a
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Small MSOP and 3mm 3mm DFN Packages
momentary switch to issue reset pulses with programmed
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Manual Reset Pin
duration. Tight voltage threshold accuracy and glitch
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Open-Drain RST Output (LTC2900-1)
immunity ensure reliable reset operation without false
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Push-Pull RST Output (LTC2900-2)
triggering. The RST output is guaranteed to be in the
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Power Supply Glitch Immunity
correct state for V down to 1V. The LTC2900-1 features
CC
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Guaranteed RST for V 1V
CC
an open-drain RST output, while the LTC2900-2 has a
push-pull RST output.
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APPLICATIO S
The 43m A supply current makes the LTC2900 ideal for
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power conscious systems and it may be configured to
Desktop and Notebook Computers
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monitor less than four inputs. The parts are available in
Multivoltage Systems
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the 10-lead MSOP and the 10-lead 3mm 3mm DFN
Telecom Equipment
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packages.
Portable Battery-Powered Equipment
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, LTC and LT are registered trademarks of Linear Technology Corporation.
Network Servers
TYPICAL APPLICATIO
Quad Supply Monitor (5V, 3.3V, 2.5V, 1.8V)
5V
3.3V
DC/DC SYSTEM
2.5V
CONVERTER LOGIC
1.8V
V3 V4
V1
LTC2900-2
V2
C1 C2
0.1F 0.1F
V
REF
RST
R1
59k
V PBR
PG
1%
GND CRT
PUSH-BUTTON
R2
RESET
40.2k C
RT
1% 47nF
2900 TA01
t = 216ms
RST
2900f
1
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ULTC2900
(Notes 1, 2, 3)
ABSOLUTE AXI U RATI GS
V1, V2, V3, V4, V , PBR ............................. 0.3V to 7V V4 Input Current ( ADJ Mode) ............................ 1mA
PG
RST (LTC2900-1)........................................ 0.3V to 7V Operating Temperature Range
RST (LTC2900-2).......................... 0.3V to (V2 + 0.3V) LTC2900-1C/LTC2900-2C ....................... 0 C to 70 C
CRT ............................................. 0.3V to (V + 0.3V) LTC2900-1I/LTC2900-2I .................... 40 C to 85 C
CC
V ............................................. 0.3V to (V + 0.3V) Storage Temperature Range .................. 65 C to 150 C
REF CC
Reference Load Current (I ) ............................ 1mA Lead Temperature (Soldering, 10 sec)................... 300 C
VREF
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PACKAGE/ORDER I FOR ATIO
ORDER PART ORDER PART
NUMBER NUMBER
TOP VIEW
LTC2900-1CMS LTC2900-1CDD
TOP VIEW
V3 1 10 V2
V3 1 10 V2
LTC2900-2CMS LTC2900-2CDD
V1 2 9 V4
V1 2 9 V4
LTC2900-1IMS LTC2900-1IDD
CRT 3 8 V
REF CRT 3 8 V
REF
RST 4 7 V
PG
RST 4 7 V
LTC2900-2IMS LTC2900-2IDD
PG
PBR 5 6 GND
PBR 5 6 GND
MS PACKAGE
MS PART MARKING DD PART MARKING
10-LEAD PLASTIC MSOP
DD PACKAGE
T = 125 C, q = 250 C/W
JMAX JA
10-LEAD (3mm 3mm) PLASTIC DFN
LTYJ LABU
T = 125 C, q = 43 C/W
JMAX JA
LTYL LABW
LTYK LABV
LTYM LABX
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25 C. V = 5V, unless otherwise noted. (Note 3)
A CC
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V 5V, 5% Reset Threshold V1 Input Threshold l 4.600 4.675 4.750 V
RT50
V 3.3V, 5% Reset Threshold V1, V2 Input Threshold l 3.036 3.086 3.135 V
RT33
V 3V, 5% Reset Threshold V2 Input Threshold l 2.760 2.805 2.850 V
RT30
V 2.5V, 5% Reset Threshold V2, V3 Input Threshold l 2.300 2.338 2.375 V
RT25
V 1.8V, 5% Reset Threshold V3, V4 Input Threshold l 1.656 1.683 1.710 V
RT18
V 1.5V, 5% Reset Threshold V3, V4 Input Threshold l 1.380 1.403 1.425 V
RT15
V ADJ Reset Threshold V3, V4 Input Threshold l 0.492 0.500 0.508 V
RTA
V ADJ Reset Threshold V4 Input Threshold l 18 0 18 mV
RTAN
V Minimum Internal Operating Voltage RST in Correct Logic State, l 1V
CC
V Rising Prior to Program
CC
V Minimum Required for Programming V Rising l 2.42 V
CCMINP CC
V Reference Voltage V 2.3V, I = 1mA, C 1000pF l 1.192 1.210 1.228 V
REF CC VREF REF
V Programming Voltage Range V V l 0V V
PG CC CCMINP REF
I V Input Current V = V l 20 nA
VPG PG PG REF
I V1 Input Current V1 = 5V, I = 12m A, (Note 4) l 43 75 m A
V1 VREF
2900f
2
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