LTC2901 Datasheet, PDF (1/16 Pages) Linear Technology – Programmable Quad Supply Monitor with Adjustable Reset and Watchdog Timers

Final Electrical Specifications
LTC2901
Programmable Quad Supply
Monitor with Adjustable Reset
and Watchdog Timers
June 2002
FEATURES
DESCRIPTIO
s _{Simultaneously Monitors Four Supplies}
s _{16 User Selectable Combinations of 5V, 3.3V, 3V,}
2.5V, 1.8V, 1.5V and/or ±Adjustable Voltage
Thresholds
s _{Guaranteed Threshold Accuracy: ±1.5% of}
Monitored Voltage Over Temperature
s _{Low Supply Current: 43µA Typ}
s _{Adjustable Reset Time}
s _{Adjustable Watchdog Time}
s _{Open-Drain RST Output (LTC2901-1)}
s _{Push-Pull RST Output (LTC2901-2)}
s _{Individual Nondelayed Monitor Output for Each Supply}
s _{Power Supply Glitch Immunity}
s _{Guaranteed RST for VCC ≥ 1V}
U
APPLICATIO S
s _{Desktop and Notebook Computers}
s _{Multivoltage Systems}
s _{Telecom Equipment}
s _{Portable Battery-Powered Equipment}
s _{Network Servers}
The LTC^®2901 is a programmable supply monitor for
systems with up to four supply voltages. One of 16 preset
or adjustable voltage monitor combinations can be se-
lected using an external resistor divider connected to the
program pin. The preset voltage thresholds are accurate
to 1.5% over temperature. All four voltage comparator
outputs are connected to separate pins for individual
supply monitoring.
The reset and watchdog delay times are adjustable using
external capacitors. Tight voltage threshold accuracy and
glitch immunity ensure reliable reset operation without
false triggering. The RST output is guaranteed to be in the
correct state for V_CC down to 1V. The LTC2901-1 features
an open-drain RST output, while the LTC2901-2 has a
push-pull RST output.
The 43µA supply current makes the LTC2901 ideal for
power conscious systems and it may be configured to
monitor less than four inputs. The parts are available in
the 16-lead narrow SSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Quadruple Supply Monitor (5V, 3.3V, 2.5V, 1.8V)
5V
3.3V
DC/DC
CONVERTER
2.5V
1.8V
C1
0.1µF
SYSTEM
LOGIC
C2
0.1µF
R1
59k
1%
R2
40.2k
1%
3 13
R3
4 ^{V3 V4}
V1
10k
2
COMP1
16
COMP2
14
LTC2901-2
1
V2
COMP3
15
COMP4
12
V_REF
8
WDI
7
WDO
11
V_PG
6
RST
GND CRT
CWT
10 5 _CRT
9 _CWT
47nF
47nF
POWER
GOOD
2901 TA01
t_RST = 216ms
t_WD = 940ms
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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