LTC2901_15 Datasheet, PDF (1/16 Pages) Linear Technology – Programmable Quad Supply Monitor with Adjustable Reset and Watchdog Timers

LTC2901
Programmable Quad Supply
Monitor with Adjustable Reset
and Watchdog Timers
FEATURES
DESCRIPTIO
■ _{Simultaneously Monitors Four Supplies}
■ _{16 User Selectable Combinations of 5V, 3.3V, 3V,}
2.5V, 1.8V, 1.5V and/or ±Adj Voltage Thresholds
■ _{Guaranteed Threshold Accuracy: ±1.5% of}
Monitored Voltage Over Temperature
■ _{Selectable Supply Tolerance: 5% and 10% Below}
Monitored Voltage (LTC2901-3/LTC2901-4)
■ _{Low Supply Current: 43μA Typ}
■ _{Adjustable Reset Time}
■ _{Adjustable Watchdog Time}
■ _{Open-Drain RST Output (LTC2901-1/LTC2901-3)}
■ _{Push-Pull RST Output (LTC2901-2/LTC2901-4)}
■ _{Individual Nondelayed Monitor Output for Each Supply}
■ _{Power Supply Glitch Immunity}
■ _{Guaranteed RST for VCC ≥ 1V}
■ _{16-Lead Narrow SSOP Package}
U
APPLICATIO S
■ _{Desktop and Notebook Computers}
■ _{Multivoltage Systems}
■ _{Telecom Equipment}
■ _{Portable Battery-Powered Equipment}
■ _{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/
LTC2901-3 features an open-drain RST output, while the
LTC2901-2/LTC2901-4 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.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Patent Pending.
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
C2
0.1μF
R1
59k
1%
R2
40.2k
1%
SYSTEM
LOGIC
V3 V4
V1
COMP1
R3
10k ^POWER
GOOD
COMP2
LTC2901-2
V2
COMP3
COMP4
V_REF
WDI
WDO
V_PG
GND CRT
RST
CWT
2901 TA01
C_RT
47nF
C_WT
47nF
t_RST = 216ms
t_WD = 940ms
Quadruple Supply Monitor (5V, 3.3V, 2.5V, 1.8V)
10% Undervoltage Monitoring, Watchdog Asserts RST
5V
3.3V
DC/DC
CONVERTER
2.5V
1.8V
C1
0.1μF
C2
0.1μF
R1
59k
1%
R2
40.2k
1%
SYSTEM
LOGIC
V3 V4
V1
COMP1
R3
10k ^POWER
GOOD
COMP2
LTC2901-4
V2
COMP3
COMP4
V_REF
WDI
TOL 5V
V_PG
GND CRT
RST
CWT
2901 TA01b
C_RT
47nF
C_WT
47nF
t_RST = 216ms
t_WD = 940ms
2901fb
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