FeaTures
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LTC2955
Pushbutton On/Off
Controller with Automatic
Turn-On
DescripTion
The
LTC
®
2955
is a micropower, pushbutton on/off control-
ler that manages system power by generating a clean enable
output from the supply monitor input and the debounced
pushbutton input. It features an interrupt output that
notifies the system of a pushbutton or low supply event.
When the system is ready, it may use the power kill input
to shut off power. If the pushbutton remains pressed for
more than the configurable turn-off duration, the system
power is forced off.
The supply input covers a wide range from 1.5V to 36V.
The robust pushbutton input handles wide voltage swings
of ±36V and ESD strikes to ±25kV (human body model)
without latchup or damage. A low 1.2µA supply current
maximizes battery run time. Separate versions are avail-
able for positive or negative enable polarities.
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.
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Automatic Turn-On Via Voltage Monitor Input
Wide Input Supply Range: 1.5V to 36V
Low Supply Current: 1.2µA
±25kV ESD HBM on
PB
Input
±36V Wide Input Voltage for
PB
Input
Low Leakage EN Output Allows DC/DC Converter
Control (LTC2955-1)
High Voltage
EN
Output Drives External P-Channel
MOSFET (LTC2955-2)
Simple Interface Allows Graceful µP Shutdown
Adjustable Turn-Off Timer
10-Lead 3mm × 2mm DFN and 8-Lead ThinSOT™
Packages
applicaTions
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Desktop and Notebook Computers
GPS Devices
Portable Instruments
Automotive Electronics
Typical applicaTion
Automatic Turn-On with Power-Fail Indication
V
TRIP
= 5.4V
8.4V
LT3008-3.3
V
IN
V
OUT
SHDN
EN
1M
R7
1M
EN
TURNS ON
STAYS ON
TURNS OFF
Pushbutton On/Off with Interrupt
TURN ON PULSE
PB
SHORT PULSE
LONG PULSE
3.3V
V
IN
2.32M
0.1µF
LTC2955DDB-1
SEL
INT
ON
KILL
PGD
POWER-FAIL
2955 TA01a
µP
INT
INTERRUPT
INTERRUPT
2955 TA01b
402k
PB
TMR GND
2955fa
For more information
www.linear.com/LTC2955
1
LTC2955
absoluTe MaxiMuM raTings
(Note 1)
V
IN
............................................................. –0.3V to 40V
Input Voltages
PB
........................................................... –40V to 40V
ON ......................................................... –0.3V to 40V
SEL ........................................................ –0.3V to 40V
KILL
......................................................... –0.3V to 6V
Output Voltages
EN/EN .................................................... –0.3V to 40V
INT
........................................................... –0.3V to 6V
PGD ......................................................... –0.3V to 6V
TMR ...................................................... –0.3V to 2.7V
Operating Temperature Range
LTC2955C ................................................ 0°C to 70°C
LTC2955I .............................................–40°C to 85°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
TSOT-23 Package ............................................. 300°C
pin conFiguraTion
TOP VIEW
INT
1
PGD 2
*EN/EN 3
V
IN
4
PB
5
11
10 ON
9
8
7
6
KILL
TMR
SEL
GND
ON
KILL
TMR
GND
1
2
3
4
TOP VIEW
8
7
6
5
INT
EN/EN*
V
IN
PB
DDB PACKAGE
10-LEAD (3mm
×
2mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 55°C/W
EXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONAL
*PIN 3 IS EN FOR LTC2955-1
AND IS
EN
FOR LTC2955-2
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
T
JMAX
= 125°C,
θ
JA
= 195°C/W
*PIN 7 IS EN FOR LTC2955-1
AND IS
EN
FOR LTC2955-2
orDer inForMaTion
Lead Free Finish
TAPE AND REEL (MINI)
LTC2955CDDB-1#TRMPBF
LTC2955CDDB-2#TRMPBF
LTC2955IDDB-1#TRMPBF
LTC2955IDDB-2#TRMPBF
LTC2955CTS8-1#TRMPBF
LTC2955CTS8-2#TRMPBF
LTC2955ITS8-1#TRMPBF
TAPE AND REEL
(http://www.linear.com/product/LTC2955#orderinfo)
PART MARKING*
LGBJ
LGBM
LGBJ
LGBM
LTGBK
LTGBN
LTGBK
PACKAGE DESCRIPTION
10-Lead (3mm × 2mm) Plastic DFN
10-Lead (3mm × 2mm) Plastic DFN
10-Lead (3mm × 2mm) Plastic DFN
10-Lead (3mm × 2mm) Plastic DFN
8-Lead Plastic TSOT-23
8-Lead Plastic TSOT-23
8-Lead Plastic TSOT-23
TEMPERATURE RANGE
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
0°C to 70°C
0°C to 70°C
–40°C to 85°C
LTC2955CDDB-1#TRPBF
LTC2955CDDB-2#TRPBF
LTC2955IDDB-1#TRPBF
LTC2955IDDB-2#TRPBF
LTC2955CTS8-1#TRPBF
LTC2955CTS8-2#TRPBF
LTC2955ITS8-1#TRPBF
8-Lead Plastic TSOT-23
–40°C to 85°C
LTC2955ITS8-2#TRMPBF
LTC2955ITS8-2#TRPBF
LTGBN
TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
2
2955fa
For more information
www.linear.com/LTC2955
LTC2955
elecTrical characTerisTics
SYMBOL
Supply
V
IN
I
IN
V
UVL
V
UVL(HYST)
Input Pins
V
PB(MIN(MAX))
V
PB
V
PB(HYST)
V
PB(VOC)
I
PB
V
ON
V
ON(HYST)
I
ON
V
KILL
V
KILL(HYST)
I
KILL
V
SEL
I
SEL
Output Pins
V
EN/EN(VOL)
V
EN(VOH)
V
EN(VOH)
I
EN
I
EN
V
INT(VOL)
I
INT
V
PGD(VOH)
V
PGD(VOL)
I
PGD
I
TMR(PU)
I
TMR(PD)
EN/EN Voltage Output Low
EN Voltage Output High (LTC2955-1)
EN
Voltage Output High (LTC2955-2)
EN Pull-Up Current (LTC2955-1)
EN
Pull-Up Resistance (LTC2955-2)
INT
Voltage Output Low
INT
Leakage Current
PGD Voltage Output High
PGD Voltage Output Low
PGD Pull-Up Current
TMR Pull-Up Current
TMR Pull-Down Current
I = 3mA
INT
= 5V
I = 0µA, –0.5µA
I = 3mA
PGD = 0V
TMR = 0V
TMR = 1.5V
I = 1mA
I = 0µA, –0.5µA
I = 0µA, –0.5µA
EN = 0V
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l
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 7V unless otherwise noted. (Note 2)
PARAMETER
Supply Voltage Range
V
IN
Supply Current
V
IN
Undervoltage Lockout
V
IN
Undervoltage Lockout Hysteresis
PB
Voltage Range
PB
Input Threshold
PB
Input Threshold Hysteresis (Note 3)
PB
Open Circuit Voltage
PB
Input Leakage Current
I = –1µA
6V <
PB
< 36V
PB
= 1V
PB
= –36V
ON Rising
DFN Package Only
ON = 1V
ON = 36V
KILL
Falling
KILL
= 1V
SEL = 1V
SEL = 36V
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l
l
l
l
l
l
l
CONDITIONS
l
l
MIN
1.5
0.5
1.0
30
–36
0.6
3.0
–1
0.76
TYP
MAX
36
UNITS
V
µA
V
mV
V
V
mV
V
µA
µA
µA
V
mV
nA
nA
V
mV
nA
V
nA
nA
V
V
V
µA
MΩ
V
nA
V
V
µA
µA
µA
1.2
1.15
85
3
1.3
200
36
V
IN
Rising
l
l
l
PB
Falling
l
0.8
40
4.3
–4
0.80
40
1
5.5
±10
–8
–400
0.84
±10
±100
ON Threshold
ON Hysteresis
ON Input Leakage Current
KILL
Input Threshold Voltage
KILL
Input Threshold Hysteresis (Note 3)
KILL
Input Leakage Current
SEL Input Threshold
SEL Input Current
0.76
0.80
30
0.84
±50
l
l
l
l
0.4
0.8
1.2
±50
±100
0.175
1.5
V
IN
– 1.5
–1.2
0.45
–2
0.9
0.4
5.5
–2.8
1.35
0.4
±50
1.5
–1.2
–2
2
–2
–3
3
5.5
0.4
–2.8
–4
4
2955fa
For more information
www.linear.com/LTC2955
3
LTC2955
elecTrical characTerisTics
SYMBOL
Timing
t
DB(ON)
t
DB(OFF)
t
TMR
t
INT(MIN)
t
ON(PD)
t
PGD(PD)
t
KILL(PD)
t
KILL(PW)
PB,
ON Turn-On Debounce Time
PB
Interrupt Debounce Time
Additional Turn-Off Debounce Time
Minimum
INT
Pulse Width
ON Interrupt Delay
PGD Propagation Delay
KILL
Propagation Delay
KILL
Minimum Pulse Width
KILL
Low, Enable Asserted
→
Enable
Released
Enable Released
→
Enable Asserted
PB
Falling or ON Rising
→
Enable Asserted
PB
Falling
→
INT
Falling
C
TMR
= 2200pF
INT
Falling
→
TMR Rising
ON Falling
→
INT
Falling, V
SEL
> 0.8V
ON Falling
→
PGD Falling
KILL
Falling
→
Enable Released
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 7V unless otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN
19
19
5.8
19
TYP
32
32
11.5
32
MAX
45
45
17.2
45
200
200
60
60
304
0.6
512
1
720
1.4
UNITS
ms
ms
ms
ms
µs
µs
µs
µs
ms
s
t
KILL(ON BLANK)
KILL
Turn-On Blanking (Note 4)
t
EN(LOCK OUT)
EN/EN Lockout Time (Note 5)
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.
Note 3:
Guaranteed by design, not subject to test.
Note 4:
The
KILL
turn-on blanking time is the waiting period immediately
after the enable output is asserted. This blanking time allows sufficient
time for the regulator and the µP to perform power-up tasks. The
KILL, PB,
and ON inputs are ignored during this period.
Note 5:
The enable lockout time is the waiting period immediately after the
enable output is released. It allows an application to properly power-down
such that the next power-up sequence starts from a consistent powered
down configuration.
PB
and ON are ignored during this period.
Typical perForMance characTerisTics
Supply Current vs Temperature
1.6
1.5
1.4
I
VIN
(µA)
I
VIN
(µA)
1.3
1.2
1.1
1.0
0.9
0.8
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
125
0.6
0
5
10
15
20 25
V
IN
(V)
1.4
1.2
1.6
V
IN
= 7V, T
A
= 25°C, unless otherwise noted.
Undervoltage Lockout vs
Temperature
1.20
Supply Current vs Supply Voltage
1.18
1.16
V
UVL
(V)
T
A
= –40°C
T
A
= 25°C
T
A
= 85°C
30
35
40
1.0
1.14
1.12
0.8
1.10
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
125
2955 G01
2955 G02
2955 G03
4
2955fa
For more information
www.linear.com/LTC2955
LTC2955
Typical perForMance characTerisTics
ON/KILL Threshold vs
Temperature
0.810
36
35
0.805
34
t
DB(ON)
(ms)
V
ON/KILL
(V)
0.800
33
32
0.795
31
0.790
–50
30
–50
1
10
t
TMR
(ms)
–25
50
25
0
75
TEMPERATURE (°C)
100
125
100
1000
V
IN
= 7V, T
A
= 25°C, unless otherwise noted.
Additional Turn-Off Debounce
Time vs TMR External Capacitance
10000
Turn-On Debounce Time
vs Temperature
–25
50
25
0
75
TEMPERATURE (°C)
100
125
1
10
100
TMR EXTERNAL CAPACITANCE (nF)
1000
2955 G06
2955 G04
2955 G05
TMR Pull-Up Current
vs Temperature
–3.4
–3.3
–3.2
I
TMR(PU)
(µA)
V
EN(VOH)
(V)
–3.1
–3.0
–2.9
–2.8
–2.7
–2.6
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
125
5.0
4.8
4.6
4.4
4.2
4.0
3.8
EN Output High Voltage vs
Temperature
5.0
EN Output High Voltage vs Supply
Voltage
4.0
3.0
V
EN(VOH)
(V)
2.0
1.0
3.6
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
125
0.0
T
A
= –40°C
T
A
= 25°C
T
A
= 85°C
1
2
3
4
V
IN
(V)
5
6
7
2955 G09
2955 G07
2955 G08
EN/EN Output Low Voltage vs
Temperature
450
400
350
V
EN/EN(VOL)
(mV)
300
250
200
150
100
50
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
125
V
IN
= 7V
V
IN
= 1.5V
I
PB
(µA)
I = 1mA
–200
–160
–120
–80
–40
0
PB
Input Current vs
PB
Voltage
300
250
PB
VOLTAGE (mV)
200
150
100
50
0
PB
Voltage vs External
PB
Resistance to Ground
40
–40
T
A
= –40°C
T
A
= 25°C
T
A
= 85°C
50
20
0
10
30
40
EXTERNAL
PB
RESISTANCE TO GROUND (k )
2955 G12
–20
0
20
PB
VOLTAGE (V)
40
2955 G11
2955 G10
2955fa
For more information
www.linear.com/LTC2955
5
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