Datasheet

LT3844
2
3844fb
PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS
(Note 1)
FE PACKAGE
16-LEAD PLASTIC TSSOP
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
V
IN
SHDN
C
SS
BURST_EN
V
FB
V
C
SYNC
f
SET
BOOST
TG
SW
V
CC
PGND
SENSE
+
SENSE
–
SGND
17
T
JMAX
= 125°C, θ
JA
= 40°C/W, θ
JC
= 10°C/W
EXPOSED PAD (PIN 17) IS SGND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3844EFE#PBF LT3844EFE#TRPBF 3844EFE 16-Lead Plastic TSSOP –40°C to 125°C
LT3844IFE#PBF LT3844IFE#TRPBF 3844IFE 16-Lead Plastic TSSOP –40°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based fi nish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to:
http://www.linear.com/tapeandreel/
Input Supply Voltage (V
IN
) ......................... 65V to –0.3V
Boosted Supply Voltage (BOOST) .............. 80V to –0.3V
Switch Voltage (SW) (Note 8) ....................... 65V to –1V
Differential Boost Voltage
BOOST to SW ........................................ 24V to –0.3V
Bias Supply Voltage (V
CC
) .......................... 24V to –0.3V
SENSE
+
and SENSE
–
Voltages ................... 40V to –0.3V
Differential Sense Voltage
SENSE
+
to SENSE
–
..................................... 1V to –1V
BURST_EN Voltage .................................... 24V to –0.3V
SYNC, V
C
, V
FB
, C
SS
and SHDN Voltages ...... 5V to –0.3V
SHDN Pin Currents ..................................................1mA
Operating Junction Temperature Range (Note 2)
LT3844E (Note 3) ............................... –40°C to 125°C
LT3844I .............................................. –40°C to 125°C
Storage Temperature .............................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 20V, V
CC
= BOOST = BURST_EN = 10V, SHDN = 2V, R
SET
= 49.9k,
SENSE
–
= SENSE
+
= 10V, SGND = PGND = SW = SYNC = 0V, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Operating Voltage Range (Note 4)
V
IN
Minimum Start Voltage
V
IN
UVLO Threshold (Falling)
V
IN
UVLO Threshold Hysteresis
l
l
l
4
3.6 3.8
670
60
7.5
4
V
V
V
mV
V
IN
Supply Current
V
IN
Burst Mode Current
V
IN
Shutdown Current
V
CC
> 9V
V
BURST_EN
= 0V, V
FB
= 1.35V
V
SHDN
= 0V
20
20
10 15
μA
μA
μA
BOOST Operating Voltage Range
BOOST Operating Voltage Range (Note 5)
BOOST UVLO Threshold (Rising)
BOOST UVLO Threshold Hysteresis
V
BOOST
– V
SW
V
BOOST
– V
SW
V
BOOST
– V
SW
l
l
5
400
75
20
V
V
V
mV
BOOST Supply Current (Note 6)
BOOST Burst Mode Current
BOOST Shutdown Current
V
BURST_EN
= 0V
V
SHDN
= 0V
1.4
0.1
0.1
mA
μA
μA