LT3980 Datasheet PDF - Linear

www.Datasheet-PDF.com

LT3980
Linear

Part Number LT3980
Description Step-Down Switching Regulator
Page 24 Pages


LT3980 datasheet pdf
Download PDF
LT3980 pdf
View PDF for Mobile


No Preview Available !

LT3980
58V, 2A, 2.4MHz
Step-Down Switching Regulator
with 85µA Quiescent Current
Features
Description
Wide Input Range: Operation from 3.6V to 58V
Overvoltage Lockout Protects Circuits Through 80V
Transients
2A Maximum Output Current
Low Ripple (<15mVP-P) Burst Mode® Operation:
IQ = 85µA at 12VIN to 3.3VOUT
Adjustable Switching Frequency: 100kHz to 2.4MHz
Low Shutdown Current: IQ < 1µA
Catch Diode Current Sense Protects Circuit Through
Short-Circuit and Input Overvoltage
Synchronizable Between 250kHz to 2MHz
Power Good Flag
Saturating Switch Design: 200mΩ On-Resistance
Thermal Protection
Soft-Start Capability
Small 16-Pin Thermally Enhanced MSOP and
3mm × 4mm DFN Packages
Applications
Automotive Battery Regulation
Distributed Supply Regulation
Industrial Supplies
Wall Transformer Regulation
The LT®3980 is an adjustable frequency (100kHz to
2.4MHz) monolithic buck switching regulator that accepts
input voltages up to 58V (80V transient). A high efficiency
200mΩ switch is included on the die along with a boost
Schottky diode and the necessary oscillator, control, and
logic circuitry. Current mode topology is used for fast
transient response and good loop stability. Catch diode
current sense (DA pin) protects the circuit during input
voltage transients even when a high switching frequency
is used. Low ripple Burst Mode operation maintains high
efficiency at low output currents while keeping output
ripple below 15mV in a typical application. In addition, the
LT3980 can further enhance low output current efficiency
by drawing bias current from the output when VOUT is
above 3V. Shutdown reduces input supply current to less
than 1µA while a resistor and capacitor on the RUN/SS
pin provide a controlled output voltage ramp (soft-start).
A power good flag signals when VOUT reaches 91% of
the programmed output voltage. The LT3980 is available
in 16-pin MSOP and 3mm × 4mm DFN packages with
exposed pads for low thermal resistance.
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.
Typical Application
5V Step-Down Converter
VIN
6.5V TO 58V
TRANSIENT
TO 80V
OFF ON
VIN
RUN/SS
BD
BOOST
10µF
4.75k
1nF
97.6k
VC LT3980
RT
PG
SYNC GND
SW
DA
FB
VOUT
5V
2A
0.47µF 10µH
22pF
536k
100k
47µF
3980 TA01
For more information www.linear.com/LT3980
Efficiency, VOUT = 5V
95
90 VIN = 12V
85 VIN = 24V
80 VIN = 48V
75
70
65
60
55 f = 400kHz
D = DIODES, INC. SBR3U100LP
50
0 0.5 1 1.5
ILOAD (A)
2
3980 TA01b
3980fa
1
Free Datasheet http://www.Datasheet4U.com



No Preview Available !

LT3980
Absolute Maximum Ratings (Note 1)
VIN, RUN/SS Voltage (Note 5)....................................80V
BOOST Pin Voltage....................................................75V
BOOST Pin Above SW Pin..........................................30V
FB, RT, VC Voltage........................................................5V
PG, BD, SYNC Voltage...............................................25V
Operating Junction Temperature Range (Note 2)
LT3980E..............................................– 40°C to 125°C
LT3980I...............................................– 40°C to 125°C
LT3980H.............................................– 40°C to 150°C
Storage Temperature Range....................–65°C to 150°C
Lead Temperature (Soldering, 10 sec)
(MSE Only)........................................................ 300°C
pIN CONFIGURATION
TOP VIEW
SYNC 1
14 DA
NC 2
13 NC
PG 3 15 12 VIN
FB 4 GND 11 SW
VC 5
RT 6
10 BOOST
9 BD
GND 7
8 RUN/SS
DE14 PACKAGE
14-LEAD (4mm × 3mm) PLASTIC DFN
θJA = 45°C/W, θJC = 10°C/W
EXPOSED PAD (PIN 15) IS GND, MUST BE SOLDERED TO PCB
SYNC 1
PG 2
NC 3
FB 4
NC 5
RVTC
6
7
GND 8
TOP VIEW
17
GND
16 NC
15 DA
14
13
VNICN
12 SW
11 BOOST
10 BD
9 RUN/SS
MSE PACKAGE
16-LEAD PLASTIC MSOP
θJA = 45°C/W, θJC = 10°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
order information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT3980EDE#PBF
LT3980EDE#TRPBF
3980
14-Lead (3mm × 4mm) Plastic DFN –40°C to 125°C
LT3980IDE#PBF
LT3980IDE#TRPBF
3980
14-Lead (3mm × 4mm) Plastic DFN –40°C to 125°C
LT3980EMSE#PBF
LT3980EMSE#TRPBF
3980
16-Lead Plastic MSOP
–40°C to 125°C
LT3980IMSE#PBF
LT3980IMSE#TRPBF
3980
16-Lead Plastic MSOP
–40°C to 125°C
LT3980HMSE#PBF
LT3980HMSE#TRPBF
3980
16-Lead Plastic MSOP
–40°C to 150°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/
E lectrical Characteristics The denotes the specifications which apply over the full operating temper-
ature range, otherwise specifications are at TA = 25°C. VIN = 10V, VRUN/SS = 10V, VBOOST = 15V, VBD = 3.3V unless otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Minimum Input Voltage
3 3.6
V
VIN Overvoltage Lockout
Quiescent Current from VIN
2
VRUN/SS = 0.2V
VVBBDD
=
=
3V, Not Switching
0, Not Switching
For more information www.linear.com/LT3980
58
20
70
61.5 64
0.01 0.5
35 60
120 160
V
µA
µA
µA
3980fa
Free Datasheet http://www.Datasheet4U.com



No Preview Available !

LT3980
E lectrical Characteristics The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 10V, VRUN/SS = 10V, VBOOST = 15V, VBD = 3.3V unless otherwise
noted. (Note 2)
PARAMETER
Quiescent Current from BD
Feedback Voltage
FB Pin Bias Current (Note 3)
FB Voltage Line Regulation
Error Amp gm
Error Amp Gain
VC Source Current
VC Sink Current
VC Pin to Switch Current Gain
VC Clamp Voltage
Switching Frequency
Minimum Switch Off-Time
Switch Current Limit
Switch VCESAT
DA Pin Current to Pause OSC
Boost Schottky Reverse Leakage
Minimum Boost Voltage (Note 4)
BOOST Pin Current
RUN/SS Pin Current
RUN/SS Input Voltage High
RUN/SS Input Voltage Low
PG Threshold Offset from Feedback Voltage
PG Hysteresis
PG Leakage
PG Sink Current
SYNC Threshold
SYNC Pin Bias Current
CONDITIONS
VRUN/SS = 0.2V
VBD = 3V, Not Switching
VBD = 0, Not Switching
VFB = 0.8V, VC = 1.2V
4V < VIN < 56V
RRTT
=
=
8.66k
29.4k
RT = 187k
Duty Cycle = 5%
ISW = 2A
VBD = 0V
ISW = 2A
VRUN/SS = 2.5V
VFB Rising
VPG = 5V
VPG = 0.4V
VSYNC = 0V
MIN
55
782
770
1.95
0.86
195
3.3
1.9
0.4
50
200
0.575
TYP
0.01
82
1
790
790
10
0.002
500
1800
60
60
3.87
2
2.25
1.07
225
140
4
540
2.4
0.02
1.7
40
6
65
14
0.1
700
0.675
0.1
MAX
0.5
115
5
798
805
40
0.01
2.55
1.27
255
230
4.9
3
2
2.2
55
10
2.5
80
1
0.775
UNITS
µA
µA
µA
mV
mV
nA
%/V
µmho
µA
µA
A/V
V
MHz
MHz
kHz
nS
A
mV
A
µA
V
mA
µA
V
V
mV
mV
µA
µA
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 LT3980E is guaranteed to meet performance specifications
from 0°C to 125°C. Specifications over the –40°C to 125°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LT3980I specifications are
guaranteed over the –40°C to 125°C temperature range. The LT3980H
specifications are guaranteed over the –40°C to 150°C operating
temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
Note 3: Bias current flows out of the FB pin.
Note 4: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the switch.
Note 5: Absolute Maximum at VIN and RUN/SS pins is 80V for non-
repetitive 1 minute transients, and 60V for continuous operation.
For more information www.linear.com/LT3980
3980fa
3
Free Datasheet http://www.Datasheet4U.com



No Preview Available !

LT3980
Typical Performance Characteristics TA = 25°C unless otherwise noted.
Efficiency, VOUT = 3.3V
90
VIN = 12V
85
80 VIN = 24V
75 VIN = 48V
70
65
60
55 f = 400kHz
D = DIODES, INC. SBR3U100LP
50
0 0.5 1 1.5
ILOAD (A)
2
3980 G01
No-Load Supply Current
130 VOUT = 3.3V
110
90
70
50
30
10
0 10 20 30 40 50 60
INPUT VOLTAGE (V)
3980 G04
Maximum Load Current,
VOUT = 5V
3.5
TYPICAL
3.0
MINIMUM
2.5
2.0
5
10 15 20 25 30 35 40 45 50 55 60
INPUT VOLTAGE (V)
3980 G07
4
Efficiency, VOUT = 5V
95
90 VIN = 12V
85 VIN = 24V
80 VIN = 48V
75
70
65
60
55 f = 400kHz
D = DIODES, INC. SBR3U100LP
50
0 0.5 1 1.5
ILOAD (A)
2
3980 G02
No-Load Supply Current
400
CATCH DIODE: DIODES, INC. PDS360
350 VIN = 12V
300 VOUT = 3.3V
250
INCREASED SUPPLY
CURRENT DUE TO CATCH
200
DIODE LEAKAGE AT
HIGH TEMPERATURE
150
100
50
0
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
3980 G05
Efficiency vs Switching Frequency
88 4.0
86 3.5
84 3.0
82 2.5
80 2.0
78 1.5
76 1.0
74
VIN = 12V
VOUT = 5V
0.5
72 IOUT = 2A
0
0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
SWITCHING FREQUENCY (MHz)
3980 G03
Maximum Load Current,
VOUT = 3.3V
3.5
TYPICAL
3.0
MINIMUM
2.5
2.0
5
10 15 20 25 30 35 40 45 50 55 60
INPUT VOLTAGE (V)
3980 G06
Switch Current Limit
5.0
4.5
4.0 TYPICAL
3.5 MINIMUM
3.0
2.5
2.0
0
20 40
60 80
DUTY CYCLE (%)
100
3980 G08
Switch Current Limit
6.5
6.0
5.5
5.0
4.5
4.0 DUTY CYCLE = 10%
3.5
3.0
2.5
2.0
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
3980 G09
3980fa
For more information www.linear.com/LT3980
Free Datasheet http://www.Datasheet4U.com



LT3980 datasheet pdf
Download PDF
LT3980 pdf
View PDF for Mobile


Related : Start with LT398 Part Numbers by
LT3980 Step-Down Switching Regulator LT3980
Linear
LT3980 pdf

Index :   0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   

This is a individually operated, non profit site. If this site is good enough to show, please introduce this site to others.
Since 2010   ::   HOME   ::   Contact