LT3990/LT3990-3.3/LT3990-5
62V, 350mA Step-Down
Regulator with 2.5A
Quiescent Current and
Integrated Diodes
FEATURES DESCRIPTION
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Low Ripple Burst Mode Operation
The LT 3990 is an adjustable frequency monolithic buck
2.5A I at 12V to 3.3V
switching regulator that accepts a wide input voltage
Q IN OUT
Output Ripple < 5mV
range up to 62V, and consumes only 2.5A of quiescent
P-P
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Wide Input Voltage Range: 4.2V to 62V Operating
current. A high efficiency switch is included on the die
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Adjustable Switching Frequency: 200kHz to 2.2MHz
along with the catch diode, boost diode, and the neces-
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Integrated Boost and Catch Diodes
sary oscillator, control and logic circuitry. Low ripple Burst
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350mA Output Current
Mode operation maintains high efficiency at low output
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Fixed Output Voltages: 3.3V, 5V
currents while keeping the output ripple below 5mV in a
2A I at 12V
typical application. Current mode topology is used for fast
Q IN
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Accurate Programmable Undervoltage Lockout
transient response and good loop stability. A catch diode
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FMEA Fault Tolerant (MSOP Package)
current limit provides protection against shorted outputs
Output Stays at or Below Regulation Voltage During
and overvoltage conditions. An accurate programmable
Adjacent Pin Short or When a Pin is Left Floating
undervoltage lockout feature is available, producing a low
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Low Shutdown Current: I = 0.7A
shutdown current of 0.7A. A power good flag signals when
Q
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Internal Sense Limits Catch Diode Current
V reaches 90% of the programmed output voltage. The
OUT
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Power Good Flag
LT3990 is available in small, thermally enhanced 16-pin
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Small, Thermally Enhanced 16-Pin MSOP
MSOP and 3mm 3mm DFN packages.
and (3mm 3mm) DFN Packages
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
APPLICATIONS
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Automotive Battery Regulation
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Power for Portable Products
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Industrial Supplies
TYPICAL APPLICATION
Power Loss
1000
V = 12V
IN
5V Step-Down Converter
100
V
IN
6.5V TO 62V
0.22F
V BOOST 10
IN
LT3990-5
33H
V
OUT
OFF ON EN/UVLO SW 5V
1
350mA
PG
BD
RT V 0.1
2.2F 22F
OUT
GND
374k
0.01
3990 TA01a
f = 400kHz
0.001 0.01 0.1 1 10 100
LOAD CURRENT (mA)
3990 TA01b
3990fa
1
POWER LOSS (mW)LT3990/LT3990-3.3/LT3990-5
ABSOLUTE MAXIMUM RATINGS (Note 1)
V , EN/UVLO Voltage ...............................................62V Operating Junction Temperature Range (Note 2)
IN
BOOST Pin Voltage ...................................................75V LT3990E/LT3990E-X ........................... 40C to 125C
BOOST Pin Above SW Pin .........................................30V LT3990I/LT3990I-X ............................ 40C to 125C
FB/V , RT Voltage ....................................................6V LT3990H/LT3990H-X .......................... 40C to 150C
OUT
PG, BD Voltage .........................................................30V Storage Temperature Range ................... 65C to 150C
Lead Temperature (Soldering, 10 sec)
MS Only ............................................................ 300C
PIN CONFIGURATION
TOP VIEW TOP VIEW
FB/V * 1 16 RT
OUT
FB/V * 2 15 NC
FB 10 RT OUT
1
NC 3 14 PG
EN/UVLO 2 9 PG
EN/UVLO 4 17 13 BD
11
NC 5 12 NC
GND
V 3 8 BD
IN
GND
V 6 11 BOOST
IN
GND 4 7 BOOST
NC 7 10 NC
GND 8 9 SW
GND 5 6 SW
MSE PACKAGE
16-LEAD PLASTIC MSOP
DD PACKAGE
10-LEAD (3mm 3mm) PLASTIC DFN
= 40C/W, = 10C/W
JA JC
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
= 45C/W, = 10C/W
JA JC
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
*FB FOR LT3990, V FOR LT3990-3.3, LT3990-5
OUT
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3990EDD#PBF LT3990EDD#TRPBF LFWJ 40C to 125C
10-Lead (3mm 3mm) Plastic DFN
LT3990IDD#PBF LT3990IDD#TRPBF LFWJ 40C to 125C
10-Lead (3mm 3mm) Plastic DFN
LT3990EMSE#PBF LT3990EMSE#TRPBF 3990 16-Lead Plastic MSOP 40C to 125C
LT3990IMSE#PBF LT3990IMSE#TRPBF 3990 16-Lead Plastic MSOP 40C to 125C
LT3990HMSE#PBF LT3990HMSE#TRPBF 3990 16-Lead Plastic MSOP 40C to 150C
LT3990EMSE-3.3#PBF LT3990EMSE-3.3#TRPBF 399033 16-Lead Plastic MSOP 40C to 125C
LT3990IMSE-3.3#PBF LT3990IMSE-3.3#TRPBF 399033 16-Lead Plastic MSOP 40C to 125C
LT3990HMSE-3.3#PBF LT3990HMSE-3.3#TRPBF 399033 16-Lead Plastic MSOP 40C to 150C
LT3990EMSE-5#PBF LT3990EMSE-5#TRPBF 39905 16-Lead Plastic MSOP 40C to 125C
LT3990IMSE-5#PBF LT3990IMSE-5#TRPBF 39905 16-Lead Plastic MSOP 40C to 125C
LT3990HMSE-5#PBF LT3990HMSE-5#TRPBF 39905 16-Lead Plastic MSOP 40C to 150C
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 non-standard lead based finish parts.
For more information on lead free part marking, go to: