OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LT3971AIMSE-5#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24
LT3971A/LT3971A-5
1
3971af
TYPICAL APPLICATION
FEATURES DESCRIPTION
APPLICATIONS
L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
The LT
®
3971A is an adjustable frequency monolithic buck
switching regulator that accepts a wide input voltage range
up to 38V. Low quiescent current design consumes only
2.8µA of supply current while regulating with no load. Low
ripple Burst Mode operation maintains high efficiency at
low output currents while keeping the output ripple below
15mV in a typical application. An internally compensated
current mode topology is used for fast transient response
and good loop stability. A high efficiency 0.33 switch
is included on the die along with a boost Schottky diode
and the necessary oscillator, control and logic circuitry.
An accurate 1V threshold enable pin can be used to shut
down the LT3971A, reducing the input supply current to
700nA.
A capacitor on the SS pin provides a controlled
inrush current (soft-start). A power good flag signals when
V
OUT
reaches 91% of the programmed output voltage. The
LT3971A is available in a small 10-lead MSOP package
with an exposed pad for low thermal resistance.
The LT3971A and LT3971A-5 have a more accurate ref-
erence voltage compared to the LT3971 and LT3971-5.
The LT3971A-5 also has specified V
OUT
pin current and
ABSMAX current. These characteristics are important for
USB applications.
n
Ultralow Quiescent Current:
2.8µA I
Q
Regulating 12V
IN
to 3.3V
OUT
n
Fixed Output Voltages: 5V
2.2µA I
Q
Regulating 12V
IN
to 5V
OUT
n
Low Ripple Burst Mode
®
Operation:
Output Ripple < 15mV
P-P
n
Wide Input Voltage Range: 4.3V to 38V
n
1.3A Maximum Output Current
n
Adjustable Switching Frequency: 200kHz to 2MHz
n
Synchronizable Between 250kHz to 2MHz
n
Fast Transient Response
n
Accurate 1V Enable Pin Threshold
n
Low Shutdown Current: I
Q
= 700nA
n
Power Good Flag
n
Soft-Start Capability
n
Internal Compensation
n
Output Voltage: 1.19V to 30V
n
Small Thermally Enhanced 10-Lead MSOP Package
n
USB VBUS Regulation
n
Automotive Battery Regulation
n
Power for Portable Products
n
Industrial Supplies
38V, 1.3A, 2MHz
Step-Down Regulator with
2.2µA Quiescent Current
5.15V Step-Down Converter for USB Applications
No Load Supply Current
INPUT VOLTAGE (V)
5
INPUT CURRENT (µA)
1.0
10 20 3015 25 35
3971A TA01b
2.0
1.5
3.0
2.5
LT3971A-5
OUTPUT IN REGULATION
SW
V
OUT
SS
RT
V
IN
V
IN
6.3V TO 38V
V
OUT
5.15V
1.3A
4.7µF
0.47µF
47µF
118k
f = 400kHz
10µH
GND
BD
SYNC
OFF ON
LT3971A-5
3971 TA01a
EN BOOST
PG
20k, 1%
715k
1%
LT3971A/LT3971A-5
2
3971af
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
(Note 1)
ORDER INFORMATION
V
IN
, EN Voltage .........................................................38V
BOOST Pin Voltage ...................................................55V
BOOST Pin Above SW Pin .........................................30V
FB, RT, SYNC, SS Voltage ...........................................6V
PG, BD Voltage .........................................................30V
V
OUT
Pin Current ....................................................–2mA
Operating Junction Temperature Range (Note 2)
LT3971AI/LT3971AI-5 ........................ –40°C to 125°C
Storage Temperature Range .............. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
(MSE Only) .......................................................300°C
LT3971A LT3971A-5
1
2
3
4
5
BD
BOOST
SW
V
IN
EN
10
9
8
7
6
11
GND
SYNC
PG
RT
SS
FB
TOP VIEW
MSE PACKAGE
10-LEAD PLASTIC MSOP
θ
JA
= 45°C, θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
1
2
3
4
5
BD
BOOST
SW
V
IN
EN
10
9
8
7
6
11
GND
SYNC
PG
RT
SS
V
OUT
TOP VIEW
MSE PACKAGE
10-LEAD PLASTIC MSOP
θ
JA
= 45°C, θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3971AIMSE#PBF LT3971AIMSE#TRPBF LTGFQ 10-Lead Plastic MSOP –40°C to 125°C
LT3971AIMSE-5#PBF LT3971AIMSE-5#TRPBF LTGFR 10-Lead Plastic MSOP –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 non-standard 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/
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
EN
= 12V, V
BD
= 3.3V unless otherwise noted. (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage (Note 4)
l
4 4.3 V
Quiescent Current from V
IN
V
EN
Low
V
EN
High, V
SYNC
Low
V
EN
High, V
SYNC
Low
l
0.7
1.7
1.2
2.7
4.5
A
A
A
LT3971A FB Pin Current V
FB
= 1.19V
l
0.1 12 nA
Internal Feedback Resistor Divider (LT3971A-5) 10 M
LT3971A/LT3971A-5
3
3971af
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 LT3971AI is guaranteed over the full –40°C to 125°C operating
junction temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
Note 3: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the switch.
Note 4: Minimum input voltage depends on application circuit.
V
OUT
Pin Current V
OUT
= 5V
V
OUT
= 5V
l
–0.65
–0.90
–0.5
–0.5
–0.38
–0.32
A
A
V
OUT
Pin Clamp Voltage I
VOUT
= –2mA 9 11 13 V
Feedback Voltage
l
1.176
1.173
1.192
1.19
1.204
1.207
V
V
LT3971A-5 Output Voltage
l
4.94
4.93
5.01
5
5.06
5.07
V
V
FB Voltage Line Regulation 4.3V < V
IN
< 38V (Note 4) 0.0002 0.01 %/V
Switching Frequency R
T
= 11k
R
T
= 35.7k
R
T
= 255k
1.8
0.8
160
2.2
1
200
2.6
1.2
240
MHz
MHz
kHz
Minimum Switch On Time 80 ns
Minimum Switch Off Time 110 150 ns
Switch Current Limit 2.0 2.5 3.2 A
Switch V
CESAT
I
SW
= 1A 330 mV
Switch Leakage Current 0.02 1 A
Boost Schottky Forward Voltage I
SH
= 100mA 770 mV
Boost Schottky Reverse Leakage V
REVERSE
= 12V 0.02 1 A
Minimum Boost Voltage (Note 3) V
IN
= 5V
l
1.4 1.8 V
BOOST Pin Current I
SW
= 1A, V
BOOST
= 15V 20 28 mA
EN Voltage Threshold EN Rising
l
0.95 1.01 1.07 V
EN Voltage Hysteresis 30 mV
EN Pin Current 0.2 20 nA
LT3971A PG Threshold Offset from V
FB
V
FB
Rising 60 100 140 mV
LT3971A PG Hysteresis 20 mV
LT3971A-5 PG Threshold Offset from V
OUT
V
OUT
Rising 5.5 9 12.5 %
LT3971A-5 PG Hysteresis 1.3 %
PG Leakage V
PG
= 3V 0.02 1 µA
PG Sink Current V
PG
= 0.4V
l
300 570 A
SYNC Threshold 0.6 0.8 1.0 V
SYNC Pin Current 0.1 nA
SS Source Current V
SS
= 1V 0.6 1 1.6 A
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
EN
= 12V, V
BD
= 3.3V unless otherwise noted. (Note 2)
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24

LT3971AIMSE-5#PBF

Mfr. #:
Buy LT3971AIMSE-5#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 40V, 1.2A, 2MHz Step-Down Switching Regulator with 2uA Quiescent Current
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet