LTC2953 Datasheet, PDF (1/20 Pages) Linear Technology – Push Button On/Off Controller with Voltage Monitoring

FEATURES
■ _{Wide Operating Voltage Range: 2.7V to 27V}
■ _{Push Button Control of System Power}
■ _{Low Supply Current: 14μA}
■ _{Power Fail Comparator Generates Warning}
■ _{UVLO Comparator Gracefully Latches Power Off}
■ _{Adjustable Supply Monitor with 200ms Reset}
■ _{Adjustable Power Down Timer}
■ _{Low Leakage EN Output (LTC2953-1) Allows DC/DC}
Converter Control
■ _{High Voltage} ⎯_E⎯_{N Output (LTC2953-2) Allows Circuit}
Breaker Control
■ _{Simple Interface Allows Orderly System Power Up}
and Power Down
■ _{±1.5% Threshold Tolerances}
■ _{±10kV ESD HBM on} ⎯_P⎯_{B Input}
■ _{12-Pin 3mm × 3mm DFN}
APPLICATIONS
■ _{Push Button Power Path Control}
■ _{Battery Power Supervisor}
■ _{Portable Instrumentation, PDA}
■ _{Blade Servers}
■ _{Desktop and Notebook Computers}
LTC2953
Push Button
On/Off Controller
with Voltage Monitoring
DESCRIPTION
The LTC^®2953 is a push button On/Off controller that
manages system power via a push button interface. An
enable output toggles system power while an interrupt
output provides debounced push button status. The inter-
rupt output can be used in menu driven applications to
request a system power down.
The LTC2953 also features input and output power sup-
ply monitors. An uncommitted power fail comparator
provides real time input monitor information, while a
de-glitched under voltage lockout comparator gracefully
initiates a system power down. The under voltage lockout
comparator prevents the system from powering from a
low power supply.
The adjustable supply monitor input is compared against
an accurate internal 0.5V reference. The reset output
remains low until the supply monitor input has been in
compliance for 200ms.
The LTC2953 operates over a wide 2.7V to 27V input
voltage range and draws only 14μA of current. Two ver-
sions of the part accommodate either positive or negative
enable polarities.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
8.4V 2150k
UVLO
V_IN
EN
V_IN
V_OUT
100k
DC/DC
3.3V
SHDN
23.2k
196k
ON/OFF
LTC2953-1
PFI
VM
499k 100k
100k
100k
100k
RST
PFO
INT
PB
KILL
RST
GPIO
INT ^SYSTEM
KILL ^LOGIC
GND
PDT
1μF
2953 TA01
t_PDT = 6.4 SECONDS
Push Button On/Off Control with Interrupt
TURN ON PULSE
SHORT
INTERRUPT PULSE
PB
LONG
TURN OFF PULSE
EN
TURNS ON
STAYS ON
TURNS OFF
INT
INTERRUPT
INTERRUPT
2954 TD01b
2953f
1