LTC2951-2_15 Datasheet, PDF (1/20 Pages) Linear Technology – Pushbutton On/Off Controller

LTC2951-1/LTC2951-2
Pushbutton On/Off
Controller
FEATURES
n _{Adjustable Pushbutton Debounce and Delay Timers}
n _{Low Supply Current: 6µA}
n _{Wide Operating Voltage Range: 2.7V to 26.4V}
n _{EN Output (LTC2951-1) Allows DC/DC Converter}
Control
n _{EN Output (LTC2951-2) Allows Circuit Breaker}
Control
n _{Simple Interface Allows Graceful µP Shutdown}
n _{High Input Voltage PB Pin with Internal Pull-Up}
Resistor
n _{±10kV ESD HBM on PB Input}
n _{Accurate 0.6V Threshold on KILL Comparator Input}
n _{8-Pin 3mm × 2mm DFN and ThinSOT}^TM _Packages
APPLICATIONS
n _{Portable Instrumentation Meters}
n _{Blade Servers}
n _{Portable Customer Service PDA}
n _{Desktop and Notebook Computers}
DESCRIPTION
The LTC^®2951 is a micropower, wide input voltage range
pushbutton ON/OFF controller. The part contains a push-
button input which controls the toggling of an open-drain
enable output. The pushbutton turn OFF debounce time
is externally programmable, while the turn ON debounce
time is fixed at 128ms. A simple microprocessor interface
allows for proper system housekeeping prior to power-
down. Under system fault conditions, an adjustable KILL
timeout delay ensures proper power-down.
The LTC2951 operates over a 2.7V to 26.4V input voltage
range to accommodate a variety of input power supplies.
Very low quiescent current (6µA typical) makes the
LTC2951 ideally suited for battery powered applications.
Two versions of the part are available to accommodate
either positive or negative enable polarities. The parts
are available in 8-pin 3mm × 2mm DFN and ThinSOT
packages.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT and PowerPath are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
TYPICAL APPLICATION
V_IN
2.7V TO 26.4V
V_IN
V_OUT
DC/DC
BUCK
SHDN**
2951 TA01
V_IN
EN
LTC2951-1 _INT
PB
KILL
GND KILLT
OFFT
R1
10k
INT
µP/µC
KILL
C_KILLT*
0.033µF
C_OFFT*
0.033µF
*OPTIONAL
**SHDN INTERNALLY PULLED UP BY DC/DC
EN
2V/DIV
PB
Turn-On Debounce
128ms
25ms/DIV
2951 TA01b
295112fb
1