LTC2951ITS8-1#TRMPBF Linear Technology, LTC2951ITS8-1#TRMPBF Datasheet - Page 11
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LTC2951ITS8-1#TRMPBF
Manufacturer Part Number
LTC2951ITS8-1#TRMPBF
Description
IC PB ON/OFF CONTROLLER TSOT23-8
Manufacturer
Linear Technology
Datasheet
1.LTC2951CDDB-1TRMPBF.pdf
(20 pages)
Specifications of LTC2951ITS8-1#TRMPBF
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
TSOT-23-8, TSOT-8
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Voltage - Input
-
Other names
LTC2951ITS8-1#TRMPBF
LTC2951ITS8-1#TRMPBFTR
LTC2951ITS8-1#TRMPBFTR
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
APPLICATIONS INFORMATION
Simplified Power-On/-Off Sequence
Figure 1 shows a simplified LTC2951-1 power-on and
power-off sequence. A high to low transition on PB (t
initiates the power-on sequence. This diagram does not
show any bounce on PB . In order to assert the enable
output, the PB pin must stay low continuously (PB high
resets timers) for 128ms (t
an internal 512ms blanking timer is started. This blank-
ing timer is designed to give sufficient time for the DC/
DC converter to reach its final voltage, and to allow the
µP enough time to perform power-on tasks.
The KILL pin must be pulled high within 512ms of the
EN pin going high. Failure to do so results in the EN
OFFT
KILL
INT
PB
EN
t
1
2
t
–t
DB, ON
1
). Once EN goes high (t
Figure 1. Simplified Power-On/-Off Sequence for LTC2951-1
t
2
PB & KILL IGNORED
t
KILL, ON BLANK
t
3
2
1
t
),
4
)
pin going low 512ms after it went high. (EN = low, see
Figure 2). Note that the LTC2951 does not sample KILL
and PB until after the 512ms internal timer has expired.
The reason PB is ignored is to ensure that the system
is not forced off while powering on. Once the 512ms
timer expires (t
debounced with an internal 32ms timer. The system has
now properly powered on and the LTC2951 monitors PB
and KILL (for a turnoff command) while consuming only
6µA of supply current.
A high to low transition on PB (t
sequence. PB must stay low continuously (PB high resets
debounce timer) for a period controlled by the default 32ms
t
5
t
DB, OFF
LTC2951-1/LTC2951-2
t
OFFT
4
), the release of the PB pin is then
t
6
PB IGNORED
OFF DELAY
< t
KILL,
t
7
5
) initiates the power-off
2951 F01
11
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