LTC2951IDDB-2#TRPBF Linear Technology, LTC2951IDDB-2#TRPBF Datasheet - Page 6

• Manufacturer Part Number: LTC2951IDDB-2#TRPBF
• Description: IC PUSH BUTTON ON/OFF CTRLR 8DFN
• Manufacturer: Linear Technology

Specifications of LTC2951IDDB-2#TRPBF

• Applications: Push Button, On/Off Controller
• Voltage - Supply: 2.7 V ~ 26.4 V
• Current - Supply: 6µA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-DFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -

PIN FUNCTIONS
LTC2951-1/LTC2951-2
V
PB (Pin 2/Pin 3): Pushbutton Input. Connecting PB to
ground through a momentary switch provides on/off
control via the EN/EN pin. An internal 100k pull-up resis-
tor connects to an internal 1.9V bias voltage. The rugged
PB input can be pulled up to 26.4V externally without
consuming extra current.
KILLT (Pin 3/Pin 2): Additional, Adjustable KILL Turn-Off
Delay Input (t
ground provides additional delay time (beyond the internal
default 128ms, t
automatic release of the enable output. The KILL turn-off
delay feature ensures the release of the enable pin under
system fault conditions, such as the µP not responding
to the LTC2951 interrupt signal (INT low).
GND (Pin 4/Pin 1): Device Ground.
INT (Pin 5/Pin 8): Open-Drain Interrupt Output. After a
pushbutton turn-off event is detected (t
the LTC2951 interrupts the system (µP) by bringing the
INT pin low. Once the system finishes its power-down and
housekeeping tasks, it sets KILL low, which in turn releases
the enable output. If at the end of the power-down timer
period (t
is still high, the enable output is released immediately.
INT may optionally be tied to KILL to release the enable
output immediately after the turn-off event has been
detected (INT low).
EN (LTC2951-1, Pin 6/Pin 7): Open-Drain Enable Output.
This pin is intended to enable system power. EN goes high
after a valid PB turn-on event (t
a) KILL is not driven high within 512ms of the initial valid
6
IN
(Pin 1/Pin 4): Power Supply Input: 2.7V to 26.4V.
KILL, OFF DELAY
KILL, OFF DELAY, ADDITIONAL
KILL, OFF DELAY
+ t
KILL, OFF DELAY, ADDITIONAL
(TSOT-23/DFN)
) from INT falling to the
DB, ON
). EN goes low if:
). A capacitor to
DB, OFF
+ t
) KILL
OFFT
),
PB power turn-on event, b) KILL is driven low during
normal operation, or c) a second valid PB event (power
turn-off) is detected. This pin can connect directly to a
DC/DC converter shutdown pin that provides an internal
pull-up. Otherwise, a pull-up resistor to an external supply
is required. The operating range for this pin is 0V to 10V.
EN (LTC2951-2, Pin 6/Pin 7): Open-Drain Enable Output.
This pin is intended to enable system power. EN is asserted
low after a valid PB turn-on event (t
high if: a) KILL is not driven high within 512ms of the initial
valid PB power turn-on event, b) KILL is driven low during
normal operation, or c) a second valid PB event (power
turn-off) is detected. This pin can connect directly to a
DC/DC converter shutdown pin that provides an internal
pull-up. Otherwise, a pull-up resistor to an external supply
is required. The operating range of this pin is 0V to 10V.
OFFT (Pin 7/Pin 6): Additional Adjustable Turn-Off Time
Input (t
ditional time (beyond the internal default 32ms, t
that the PB pin must be held low before initiating a power-
down sequence (INT falling). Floating this pin results in a
default turn-off debounce time of 32ms.
KILL (Pin 8/Pin 5): KILL Input. Forcing KILL low releases
the enable output. During system turn-on, this pin is
blanked by a 512ms internal timer (t
allow the system to pull KILL high. This pin has an accu-
rate 0.6V threshold and can be used as a voltage monitor
input. If unused, connect to a low voltage output supply
(see Figure 6).
Exposed Pad (Pin 9): Exposed Pad may be left open or
connected to device ground.
OFFT
). A capacitor to ground determines the ad-
DB, ON
KILL, ON BLANK
). EN releases
DB, OFF
295112fb
) to
)