LT3991EMSE-3.3#PBF Linear Technology, LT3991EMSE-3.3#PBF Datasheet - Page 6

• Manufacturer Part Number: LT3991EMSE-3.3#PBF
• Description: IC, DC-DC CONV, 2MHz, MSOP10
• Manufacturer: Linear Technology

Specifications of LT3991EMSE-3.3#PBF

• Primary Input Voltage: 55V
• No. Of Outputs: 1
• Output Voltage: 3.3V
• Output Current: 1.2A
• No. Of Pins: 10
• Operating Temperature Range: -40°C To +125°C
• Peak Reflow Compatible (260 C): Yes
• Msl: MSL 1 - Unlimited
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

LT3991/LT3991-3.3/LT3991-5
TYPICAL PERFORMANCE CHARACTERISTICS
6
900
800
700
600
500
400
300
200
100
5.0
4.8
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
3.0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
0
0
0
LT3991-X Frequency Foldback
Minimum Input Voltage
Boost Diode Forward Voltage
V
OUT
V
OUT
200
250
= 3.3V
20
BOOST DIODE CURRENT (mA)
TO RUN
(% OF REGULATION VOLTAGE)
LOAD CURRENT (mA)
TO START
400
500
40
600
750
60
1000
800
80
1000
1250
3991 G30
3991 G19
3991 G22
1200
1500
100
400
350
300
250
200
150
100
6.4
6.2
6.0
5.8
5.6
5.4
5.2
5.0
50
95
94
93
92
91
90
89
88
87
86
85
0
–55
–55
Minimum Switch On-Time/
Switch Off-Time
0
Minimum Input Voltage
Power Good Threshold
V
OUT
t
OFF(MIN)
–25
–25
TO RUN
200
= 5V
LOAD CURRENT (mA)
5
TO START
5
0.5A LOAD
TEMPERATURE (°C)
400
TEMPERATURE (°C)
35
35
t
600
OFF(MIN)
t
ON(MIN)
65
65
800
1A LOAD
95
95
1000
125
125
T
3991 G20
3991 G17
3991 G23
A
1200
= 25°C, unless otherwise noted.
155
155
100mV/DIV
500mA/DIV
V
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
OUT
2.5
2.0
1.5
1.0
0.5
I
0
L
–55
0
Soft-Start
V
C
EN Threshold
Transient Load Response,
Load Current Stepped from 25mA
(Burst Mode Operation) to 525mA
IN
OUT
= 48V, V
0.25
RISING THRESHOLD
–25
= 47µF
0.5
OUT
FALLING THRESHOLD
5
SS PIN VOLTAGE (V)
TEMPERATURE (°C)
0.75
= 3.3V
35
10µs/DIV
1
65
1.25
95
1.5
125
1.75
3991 G18
3991 G24
3971 G21
3991fa
155
2