(Note 2)...................................................... –40 to 125°C
Operating Junction Temperature Range
(Note 2)...................................................... –40 to 125°C
Storage Temperature Range ...................... –65 to 125°C
16 15 14 13
UD PACKAGE
16-LEAD (3mm
×
3mm) PLASTIC QFN
θ
JA
= 68°C/W,
θ
JC
= 7.5°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LT3905EUD#PBF
LT3905IUD#PBF
TAPE AND REEL
LT3905EUD#TRPBF
LT3905IUD#TRPBF
PART MARKING*
LGGP
LGGP
PACKAGE DESCRIPTION
16-Lead (3mm
×
3mm) Plastic QFN
16-Lead (3mm
×
3mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°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/
FB
2
3905fa
For more information
www.linear.com/LT3905
LT3905
elecTrical characTerisTics
PARAMETER
Operating Voltage Range
Supply Current
V
ENUVLO
= 0V, Device in Shutdown
V
ENUVLO
= 1.1V, Before Trip Point
V
ENUVLO
= 1.3V, V
FB
= 2V, Switcher Standby
V
ENUVLO
= 1.3V, V
FB
= 1.5V, Not Switching
V
CTRL
= 1.5V
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= V
ENUVLO
= V
CTRL
= 3.3V unless otherwise noted.
CONDITIONS
MIN
2.7
0.1
6
250
650
1.238
1.223
1.248
0.005
l
TYP
MAX
12
1
10
350
750
1.258
1.273
0.025
75
1.95
13
75
2.5
2.5
50
175
0.215
0.204
0.108
0.104
0.055
0.052
4.2
1.1
2.2
UNITS
V
µA
µA
µA
µA
V
V
%/V
nA
V
mV
mV
nA
V
V
nA
nA
nA
Feedback Voltage (V
FB
)
Feedback Line Regulation
FB Pin Bias Current
FB Standby Threshold
FB Standby Threshold Hysteresis
CTRL to FB Offset
CTRL Input Bias Current
MON Pin Voltage Clamp
LOS_MON Pin Voltage Clamp
MON Pin Bias Current
LOS_MON Pin Bias Current
ILIM_MON Pin Bias Current
APD Monitor (MON) Current Gain
APD Loss of Signal Monitor (LOS_MON)
Current Gain
APD Current Limit Monitor (ILIM_MON) Current
Gain
APD Monitor Voltage Drop
Boost Converter
Switching Frequency
Maximum Duty Cycle
Switch Current Limit
Switch On-Resistance
Switch Leakage Current
Schottky Forward Voltage
Schottky Reverse Leakage
Loss Of Signal Comparator
Loss of Signal Comparator Internal Threshold
Loss of Signal Comparator External Threshold
Loss of Signal Comparator Hysteresis
2.7V ≤ V
IN
≤ 12V
V
FB
Rising
V
CTRL
= 0.5V
Current Out of Pin, V
CTRL
= 0.5V
I
APD
= 300µA, R
MON
= Open
I
APD
= 300µA, R
LOS_MON
= Open
Current Out of Pin, I
APD
= 0A, V
MON
= 1V
Current Out of Pin, I
APD
= 0A, V
LOS_MON
= 1V
Current Out of Pin, I
APD
= 0A, V
ILIM_MON
= 1V
300nA ≤ I
APD
≤ 3µA, 12V ≤ MONIN ≤ 65V
3µA ≤ I
APD
≤ 3mA, 12V ≤ MONIN ≤ 65V
3µA ≤ I
APD
≤ 30µA, 12V ≤ MONIN ≤ 65V
30µA ≤ I
APD
≤ 3mA, 12V ≤ MONIN ≤ 65V
30µA ≤ I
APD
≤ 300µA, 12V ≤ MONIN ≤ 65V
300µA ≤ I
APD
≤ 3mA, 12V ≤ MONIN ≤ 65V
MONIN – APD at I
APD
= 3mA, MONIN = 65V
f
SEL
= 0V
f
SEL
= 2V
f
SEL
= 0V
f
SEL
= 2V
I
SW
= 150mA
SW = 65V
I
SCHOTTKY
= 150mA
V
OUT
– SW = 65V
LOS_ADJ = 1.5V, LOS_MON Falling
LOS_ADJ = 1.0V, LOS_MON Falling
LOS_MON Rising
l
l
l
l
l
l
l
l
l
l
l
l
l
15
1.65
–13
1.80
50
0
15
2.35
2.35
0
10
35
0.185
0.196
0.092
0.096
0.045
0.048
3.7
0.9
1.8
90
80
350
0.20
0.20
0.10
0.10
0.05
0.05
3.95
1
2
95
90
400
0.75
0.1
780
V
MHz
MHz
%
%
450
3
3
mA
Ω
µA
mV
µA
V
V
mV
1.185
0.950
1.248
20
1.310
1.050
3905fa
For more information
www.linear.com/LT3905
3
LT3905
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= V
ENUVLO
= V
CTRL
= 3.3V unless otherwise noted.
PARAMETER
Current Regulation Buffer Amplifier
ILIM_MON Voltage Regulation Threshold (V
IFB
)
ILIM_MON APD Current Limit Threshold (V
ILIM
)
l
elecTrical characTerisTics
CONDITIONS
V
FB
= 0.5V
MIN
1.223
1.211
1.323
1.311
V
ILIM
– 30
TYP
1.248
1.348
10
MAX
1.273
1.285
1.373
1.385
V
ILIM
– 2
UNITS
V
V
V
V
μA/V
mV
mV
l
ILIM_MON APD Current Limit Line Regulation
ILIM_MON Indicator Threshold
ILIM_MON Indicator Hysteresis
Inputs/Outputs
EN/UVLO Threshold
EN/UVLO Internal Hysteresis
EN/UVLO Hysteresis Current
f
SEL
Voltage Threshold
f
SEL
Threshold Hysteresis
f
SEL
Input Bias Current
LOS Open Drain ON Resistance
LOS Output Low Voltage
LOS Off-State Leakage
ILIM
Open Drain ON Resistance
ILIM
Output Low Voltage
ILIM
Off-State Leakage
V
APD
= 0V, ∆I
APD
/∆V
MONIN
, 5V < V
MONIN
< 65V
V
ILIM_MON
Rising
l
V
ILIM
– 10
30
V
ENUVLO
Falling
l
1.128
1.104
1.200
1.200
25
3
0
1.272
1.296
V
V
mV
µA
µA
V
ENUVLO
Rising
V
ENUVLO
= 1.1V, Device in Shutdown
V
ENUVLO
= 1.3V, Device in Operation
f
SEL
Rising
0.700
0.900
50
0
1.100
V
mV
µA
Ω
I
LOS
= 1mA
I
LOS
= 2mA
V
IN
= V
LOS
= 12V
I
ILIM
= 1mA
I
ILIM
= 2mA
V
ILIM
= 12V
100
0.3
1
100
0.3
1
V
µA
Ω
V
µA
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 LT3905E is guaranteed to meet specified performance
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
LT3905I is guaranteed to meet performance specifications over the –40°C