FB Voltage ...................................................................5V
SHDN, f
SET
, CTRL Voltage .........................................16V
MON Voltage .............................................................12V
Operating Temperature Range
(Note 2).................................................... –40°C to 85°C
Maximum Junction Temperature .......................... 125°C
Storage Temperature Range................... –65°C to 125°C
16 15 14 13
NC 1
APD 2
MONIN 3
V
OUT2
4
5
V
OUT1
6
PUMP
7
SW
8
SW
17
12 SHDN
11 V
IN
10 GND
9
GND
UD PACKAGE
16-LEAD (3mm
×
3mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 68°C/W,
θ
JC
= 4.2°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3482EUD#PBF
LT3482IUD#PBF
TAPE AND REEL
LT3482EUD#TRPBF
LT3482IUD#TRPBF
PART MARKING*
LCFG
LCFG
PACKAGE DESCRIPTION
16-Lead (3mm × 3mm) Plastic QFN
16-Lead (3mm × 3mm) Plastic QFN
TEMPERATURE RANGE
0°C to 85°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.
For more information on lead free parts, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
PARAMETER
Minimum Operating Voltage
Maximum Operating Voltage
Feedback Voltage
Feedback Line Regulation
FB Pin Bias Current
Supply Current
Switching Frequency
Maximum Duty Cycle
Switch Current Limit
Switch V
CESAT
Switch Leakage Current
Schottky Forward Voltage
Schottky Reverse Leakage
SHDN Voltage High
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 3V, V
⎯
S
⎯
H
⎯
D
⎯
N
= 3V unless otherwise noted.
CONDITIONS
MIN
2.5
16
CTRL = 1.5V
●
●
CTRL
MON
f
SET
FB
FB = 1.3V, Not Switching
V
⎯
S
⎯
H
⎯
D
⎯
N
= 0
f
SET
= 0V
f
SET
= 2V
f
SET
= 0V
I
SW
= 150mA
SW = 5V
I
SCHOTTKY
= 150mA
V
OUT1
– SW = 50V
1.5
580
1.0
95
280
2
U
W W
W
PIN CONFIGURATION
TOP VIEW
TYP
MAX
UNITS
V
V
V
V
%/V
nA
mA
µA
kHz
MHz
%
mA
mV
µA
mV
µA
V
3482fa
1.215
1.200
1.235
0.025
30
3.3
0.1
650
1.1
360
130
880
1.255
1.260
0.07
100
4.0
0.5
750
1.3
420
220
2
5
LT3482
ELECTRICAL CHARACTERISTICS
PARAMETER
SHDN Voltage Low
SHDN Pin Bias Current
f
SET
Voltage High
f
SET
Voltage Low
f
SET
Bias Current
CTRL to FB Offset
APD Current Monitor Gain
Monitor Output Voltage Clamp
APD Monitor Voltage Drop
MONIN Pin Current Limit
MONIN – APD at I
APD
= 1mA, MONIN = 90V
APD = 0V, MONIN = 40V
15
f
SET
= 2V
CTRL = 0.5V
I
APD
= 250nA, 10V ≤ MONIN ≤ 90V
I
APD
= 2.5mA, 20V ≤ MONIN ≤ 90V
●
●
●
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 3V, V
⎯
S
⎯
H
⎯
D
⎯
N
= 3V unless otherwise noted.
CONDITIONS
MIN
TYP
35
1.5
0.4
22
–5
–10
0.180
0.185
2
2
0.20
0.20
11.5
5
40
10
15
0.215
0.215
V
V
mA
MAX
0.4
50
UNITS
V
µA
V
V
µA
mV
mV
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 reli-
ability and lifetime.
Note 2:
The LT3482E is guaranteed to meet specified performance from
0°C to 85°C. Specifications over the –40°C to 85°C operating temperature
range are assured by design, characterization and correlation with statisti-
cal process controls. The LT3482I is guaranteed to meet performance
specifications over the –40°C to 125°C operating temperature range.
3482fa
3
LT3482
TYPICAL PERFOR A CE CHARACTERISTICS
(T
A
= 25°C unless otherwise specified)
Oscillator Frequency vs
Temperature
1200
1100
f
SET
= 2V
FREQUENCY (kHz)
1000
900
800
700
600
500
–50 –25
400
350
SWITCH CURRENT LIMIT (mA)
SWITCH CURRENT LIMIT (mA)
300
250
200
150
100
50
50
25
75
0
TEMPERATURE (°C)
100
125
0
0
20
60
DUTY CYCLE (%)
40
80
100
3482 G02
f
SET
= 0V
Current Monitor Output vs MONIN
22
I
APD
= 100µA
1.0E-02
1.0E-03
21
I
MON
(µA)
I
MON
(A)
1.0E-04
1.0E-05
1.0E-06
1.0E-07
1.0E-08
18
10
20
30
40 50 60
MONIN (V)
70
80
90
20
ERROR (%)
19
Current Monitor Voltage Drop
vs Reference Current
7
6
5
4
3
2
1
0
1.00E-07
V
CESAT
(mV)
300
250
FB PIN VOLTAGE (V)
MONIN – APD (V)
1.00E-05
1.00E-03
REFERENCE CURRENT (A)
!"& / %
4
U W
3482 G01
3482 G04
Switch Current Limit
vs Duty Cycle
360
340
320
300
280
260
240
220
Switch Current Limit vs
Temperature
200
–50 –25
0
50
75
25
TEMPERATURE (°C)
100
125
3482 G03
APD Current Monitor Accuracy
MONIN = 90V
2
APD Current Monitor Accuracy
vs Temperature
MONIN = 90V
0
–2
–4
–6
–8
–10
–50 –25
I
APD
= 2.5mA
I
APD
= 10µA
I
APD
= 250nA
50
25
75
0
TEMPERATURE (°C)
100
125
1.0E-09
1.0E-08
1.0E-06
1.0E-04
I
APD
(A)
1.0E-02
3482 G05
3482 G06
Switch Saturation Voltage (V
CESAT
)
1.25
FB Pin Voltage vs Temperature
200
150
100
50
0
0
50
100 150 200 250 300
SWITCH CURRENT (mA)
350
1.24
V
IN
= 16V
V
IN
= 3V
1.23
1.22
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
3482 G08
3482 G09
3482fa
LT3482
PI FU CTIO S
APD (Pin 2):
Connect APD cathode to this pin.
MONIN (Pin 3):
Current Monitor Power Supply Pin. An
external lowpass filter can be included here to further
reduce supply voltage ripple.
V
OUT2
(Pin 4):
Voltage Doubler Output Pin. Put a 50V
rated capacitor between this pin and V
OUT1
. Tie a resistor
divider to the FB pin and GND.
V
OUT1
(Pin 5):
Boost Output Pin. Put a capacitor between
this pin and the GND plane. Minimize the length of the
trace to the capacitor.
PUMP (Pin 6):
Charge Pump Pin. Put a 50V rating bypass
capacitor between SW and PUMP to form a complete volt-
age doubler with the internal integrated Schottky diodes.
Minimize trace length to the capacitor.
SW (Pins 7, 8):
Switch Pin. Minimize the trace length on
this pin to reduce EMI.
GND (Pins 9, 10):
Ground. Pins connected internally. For
best performance, connect both pins to board ground.
V
IN
(Pin 11):
Input Supply Pin. This pin must be locally
bypassed.
SHDN (Pin 12):
Shutdown Pin. Tie to 1.5V or higher to
enable device; 0.4V or less to disable device. This pin also
functions as soft-start between 1.5V and 2V.
CTRL (Pin 13):
Internal Reference Override Pin. This allows
the FB voltage to be externally set between 0V and 1.2V.
Tie this pin higher than 1.5V to use the internal reference
of 1.235V.
FB (Pin 14):
Feedback Pin. Connect the output resistor
divider tap here.
f
SET
(Pin 15):
Oscillator Frequency Selection Pin. Tie this
pin to above 1.5V or higher to select the higher switching
frequency of 1.1MHz. For lower switching frequency, tie
to GND.
MON (Pin 16):
Current Monitor Output Pin. It sources a
current equal to 20% of the APD current and converts to
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