LT8631EFE (Note 2) ............................... –40°C to 125°C
LT8631IFE (Note 2) ................................ –40°C to 125°C
LT8631HFE (Note 2) ............................... –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
21
GND
TR/SS 10
FE PACKAGE
VARIATION FE20(16)
20-LEAD PLASTIC TSSOP
θ
JA
= 40°C/W,
θ
JC(PAD)
= 10°C/W
EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT8631EFE#PBF
LT8631IFE#PBF
LT8631HFE#PBF
TAPE AND REEL
LT8631EFE#TRPBF
LT8631IFE#TRPBF
LT8631HFE#TRPBF
http://www.linear.com/product/LT8631#orderinfo
PART MARKING*
LT8631FE
LT8631FE
LT8631FE
PACKAGE DESCRIPTION
20-Lead Plastic TSSOP
20-Lead Plastic TSSOP
20-Lead Plastic TSSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
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
8631fb
For more information
www.linear.com/LT8631
LT8631
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 15V, V
EN/UV
= 2V, unless otherwise specified. (Note 2)
PARAMETER
EN/UV Voltage Threshold
EN/UV Voltage Hysterisis
EN/UV Input Current
V
IN
Undervoltage Lockout
Quiescent Current from V
IN
Quiescent Current from V
IN
Quiescent Current from V
OUT
V
IN
Current in Regulation
Feedback Bias Current
Feedback Voltage (V
FBREF
)
Feedback Voltage Line Regulation
Feedback Voltage Load Regulation
Track/Soft-Start Source Current
Track/Soft-Start VOH
Track/Soft-Start Sink Current
Track/Soft-Start VOL
Track/Soft-Start to Feedback Offset
PG Leakage Current
PG Lower Threshold % of V
FBREF
(Note 5)
PG Upper Threshold % of V
FBREF
(Note 5)
PG Hysterisis (Note 5)
PG Sink Current
Switching Frequency
V
FB
= 0.7V, V
PG
= 0.2V
R
RT
=187kΩ, V
VOUT
= 5V, I
LOAD
= 100mA
R
RT
= 19.6kΩ, V
VOUT
= 5V, I
LOAD
= 100mA
R
RT
= 8.66kΩ, V
VOUT
= 5V, I
LOAD
= 100mA
V
IN
= 15V to 25V, R
RT
= 8.66kΩ, V
VOUT
= 1.5V, I
LOAD
= 500mA
V
IN
= 5V, R
RT
= 8.66kΩ, V
VOUT
= 5V, I
LOAD
= 500mA
1.4
V
IN
= 7.5V, R
RT
= 19.6kΩ, V
VOUT
= 5V, L = 15µH
V
IN
= 50V, R
RT
= 19.6kΩ, V
VOUT
= 5V, L = 15µH
V
SW
= 0V, V
EN/UV
= 0V
V
SW
= 100V, V
IN
=100V, V
EN/UV
= 0V
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
V
EN/UV
Rising
MIN
l
TYP
1.19
17
5
2.8
5
16
3.6
MAX
1.24
25
100
3.05
7
30
5.6
25
64
22
45
160
350
650
820
0.2
–2.5
3.2
45
75
25
200
–4.5
10.5
2.3
125
540
1075
120
UNITS
V
mV
nA
V
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
nA
mV
%/V
%/A
µA
V
µA
mV
mV
µA
nA
%
%
%
µA
kHz
kHz
kHz
ns
ns
mA
1.14
9
V
FB
= 0.9V
V
EN/UV
= 0V
V
FB
= 0.9V, V
VOUT
= 0V
V
FB
= 0.9V, V
VOUT
= 5V
V
EN/UV
= 0V
V
FB
= 0.9V, V
VOUT
= 0V
V
FB
= 0.9V, V
VOUT
= 5V
V
FB
= 0.9V, V
VOUT
= 5V
V
VOUT
= 5V, I
LOAD
= 100µA
V
VOUT
= 5V, V
SYNC/MODE
= 2V, I
LOAD
= 100µA
V
VOUT
= 5V, I
LOAD
= 1mA
V
FB
= 0.8V
V
VOUT
= 5V, I
LOAD
= 100mA
V
IN
= 7V to 100V, V
OUT
= 5V, I
LOAD
= 500mA
V
IN
= 15V, V
OUT
= 5V, I
LOAD
= 100mA to 1A
V
FB
= 0.9V, V
TR/SS
= 0V
V
FB
= 0.9V
V
FB
= 0.7V, V
TR/SS
= 1V
V
FB
= 0V
V
TR/SS
= 0.4V, V
VOUT
= 5V, I
LOAD
= 100mA
V
FB
= 0V, V
PG
= 100V
V
FB
Rising
V
FB
Falling
l
2.74
l
l
l
l
5
16
3.6
10
90
180
475
–25
–15
808
0.01
–0.3
–4.5
3.0
30
50
–25
180
–200
5
230
0
–7.5
7.5
1.9
980
75
460
925
100
500
1000
100
190
280
2.1
1.35
1.8
50
0.5
775
550
l
796
–1.5
–6.5
2.9
15
Track/Soft-Start Sink Current POR (Note 4) V
FB
= 0.9V, V
TR/SS
= 0.2V
l
l
–10.5
4.5
1.4
Minimum Switch ON Time
Minimum Switch OFF Time
IND to V
OUT
Burst Current (Note 6)
IND to V
OUT
Peak Current (Note 7)
Maximum V
OUT
Current in Regulation
Switch Pin Leakage Current
Top Switch On-Resistance
Bottom Switch On-Resistance
BST Pin Current
2.8
1.8
2.4
500
2.0
A
A
A
nA
µA
mΩ
mΩ
µA
1.00
1.2
V
BST
= 18V
180
8631fb
For more information
www.linear.com/LT8631
3
LT8631
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
J
= 25°C. V
IN
= 15V, V
EN/UV
= 2V, unless otherwise specified. (Note 2)
PARAMETER
BST Pin Threshold (Note 8)
SYNC/MODE Pin Current
SYNC/MODE Threshold
Synchronization Range
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:
The LT8631EFE is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT8631IFE is guaranteed over the full –40°C to 125°C operating junction
temperature range. The LT8631HFE is guaranteed over the full –40°C to
150°C operating junction temperature range. High junction temperatures
degrade operating lifetimes. Operating lifetime is derated at junction
temperatures greater than 125°C.
Note 3:
The LT8631 includes overtemperature protection that is intended
to protect the device during thermal overload conditions. Internal junction
temperature will exceed 150°C when the overtemperature circuitry is
active.
V
SYNC/MODE
= 3V
2
1.0
100
CONDITIONS
MIN
TYP
2.4
3.4
1.5
5.5
2.0
1000
MAX
UNITS
V
µA
V
kHz
ELECTRICAL CHARACTERISTICS
Note 4:
An internal power on reset (POR) latch is set on the positive
transition of the EN/UV pin through its threshold or thermal shutdown.
The output of the latch activates a current source on the TR/SS pin which
typically sinks 230µA while discharging the TR/SS capacitor. The latch is
reset when the TR/SS pin is driven below the soft-start POR threshold or
the EN/UV pin is taken below its threshold.
Note 5:
The threshold is expressed as a percentage of the feedback
reference voltage.
Note 6:
The IND to V
OUT
burst current is defined as the maximum value of
current flowing from the IND pin to the V
OUT
during a switch cycle when
operating in Burst Mode.
Note 7:
The IND to V
OUT
peak current is defined as the maximum value of
current flowing from the IND pin to the V
OUT
during a switch cycle.
Note 8:
The BST pin threshold is defined as the minimum voltage between
the BST and SW pins to keep the top switch on. If the the voltage falls
below the threshold when the top switch is on, a minimum switch off