QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1090A
PUSH BUTTON ON/OFF CONTROLLER WITH MICROPROCESSOR INTERRUPT
1
LTC2954-2
DESCRIPTION
Demonstration Circuit 1090A features the LTC2954-2,
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 pro-
vides a debounced push button status. The interrupt
output can be used in menu driven applications to re-
quest a system power down. A power kill input allows
a microprocessor or system to reset the enable out-
put, effectively powering down the system. Independ-
ently adjustable On and Off timers allow dependable
push button control of the enable output and resis-
tance to accidental toggling of system power.
The LTC2954 operates over a wide 2.7V to 26.4V
input voltage range to accommodate a wide variety
of input power supplies. Very low quiescent current
(6
µ
A typical) makes the LTC2954 ideally suited for
battery powered applications. Two versions of the
part are available to accommodate either positive or
negative enable polarities. The inversion of /EN of
the LTC2954-2 is found in the LTC2954-1
Design files for this circuit board are available.
Call the LTC factory
.
LTC is a trademark of Linear Technology Corporation
QUICK START PROCEDURE
Demonstration circuit 1090A is easy to set up to evalu-
ate the performance of the LTC2954-2:
1.
Place jumpers in the following positions:
CON
CPD
UNTIE
2.
Connect the input power supply of 2.7V to 26.4V
across VIN and GND or a 9V battery to the battery
connector.
3.
Push and hold the push button once to turn on the
green LED.
4.
Push and hold again on the push button to turn off
the green LED.
Figure 1.
DC1090A Example Setup
JP1
JP2
JP3