ltc2954cddb-2-trpbf Linear Technology Corporation, ltc2954cddb-2-trpbf Datasheet - Page 6

• Manufacturer Part Number: ltc2954cddb-2-trpbf
• Description: Push Button On/off Controller With ?p Interrupt
• Manufacturer: Linear Technology Corporation

PI FU CTIO S
LTC2954
6
V
⎯ P ⎯ B (Pin 2/Pin 3): Push Button Input. Connecting ⎯ P ⎯ B to
ground through a momentary switch provides On/Off
control via the EN/ ⎯ E ⎯ N and ⎯ I ⎯ N ⎯ T outputs. An internal 100k
pull-up resistor connects to an internal 1.9V bias voltage.
The rugged ⎯ P ⎯ B input withstands ±10kV ESD HBM and
can be pulled up to 26.4V externally without consuming
extra current.
ONT (Pin 3/Pin 2): Turn On Time Input. Placing an external
capacitor to ground determines the additional time (6.4
seconds/µF) the ⎯ P ⎯ B pin must be held low before the enable
output is asserted. Floating this pin results in a default turn
on debounce time of 32ms.
GND (Pin 4/Pin 1): Device Ground.
⎯ I ⎯ N ⎯ T (Pin 5/Pin 8): Open Drain Interrupt Output. After a push
button turn off event is detected (t
interrupts the system (µP) by asserting the ⎯ I ⎯ N ⎯ T pin low.
The µP would perform power down and housekeeping
tasks and then assert the ⎯ K ⎯ I ⎯ L ⎯ L pin low, thus releasing the
enable output. The ⎯ I ⎯ N ⎯ T pulse width is a minimum of 32ms
and stays low as long as ⎯ P ⎯ B is asserted. If ⎯ P ⎯ B is asserted
for longer than t
are immediately released.
EN (LTC2954-1, Pin 6/Pin 7): Open Drain Enable Output.
This pin is intended to enable system power. EN is asserted
high after a valid ⎯ P ⎯ B turn on event (t
IN
U
(Pin 1/Pin 4): Power Supply Input: 2.7V to 26.4V.
U
PD,Min
U
+ t
PDT
(TSOT-23/DFN)
, the ⎯ I ⎯ N ⎯ T and EN/ ⎯ E ⎯ N outputs
DB,OFF
DB,ON
), the LTC2954
+ t
ONT
). EN is
released low if: a) ⎯ K ⎯ I ⎯ L ⎯ L is not driven high (by μP) within
512ms of the initial valid ⎯ P ⎯ B power turn-on event, b) ⎯ K ⎯ I ⎯ L ⎯ L
is driven low during normal operation, c) ⎯ P ⎯ B is pressed
and held low (t
operating range for this low leakage pin is 0V to 26.4V.
⎯ ⎯ E ⎯ N (LTC2954-2, Pin 6/Pin 7): Open Drain Enable Bar
Output. This pin is intended to enable system power. ⎯ E ⎯ N is
asserted low after a valid ⎯ P ⎯ B turn-on event (t
⎯ E ⎯ N releases high if: a) ⎯ K ⎯ I ⎯ L ⎯ L is not driven high (by μP) within
512ms of the initial valid ⎯ P ⎯ B power turn-on event, b) ⎯ K ⎯ I ⎯ L ⎯ L
is driven low during normal operation, c) ⎯ P ⎯ B is pressed
and held low (t
The operating range of this pin is 0V to 26.4V.
PDT (Pin 7/Pin 6): Power Down Time Input. A capacitor
to ground determines the additional time (6.4 seconds/µF)
that the push button must be held low before immediately
releasing the EN/ ⎯ E ⎯ N and ⎯ I ⎯ N ⎯ T outputs. Floating this pin
results in a push button power down time of 64ms.
⎯ K ⎯ I ⎯ L ⎯ L (Pin 8/Pin 5): Kill Input. Forcing ⎯ K ⎯ I ⎯ L ⎯ L low releases the
enable output. During system turn on, this pin is blanked
by a 512ms internal timer (t
system to pull ⎯ K ⎯ I ⎯ L ⎯ L high. This pin has an accurate 0.6V
threshold and can be used as a voltage monitor input.
Exposed Pad (Pin 9 DFN Only): Exposed Pad may be left
open or connected to device ground.
PD, Min
PD, Min
+ t
+ t
PDT
PDT
) during normal operation. The
⎯ K ⎯ I ⎯ L ⎯ L , ON BLANK
) during normal operation.
) to allow the
DB, ON
+ t
ONT
2954fa
).