|
|
PDF LT3080-1 Data sheet ( Hoja de datos )
| Número de pieza | LT3080-1 | |
| Descripción | Parallelable 1.1A Adjustable Single Resistor Low Dropout Regulator | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LT3080-1 (archivo pdf) en la parte inferior de esta página. Total 24 Páginas | ||
|
No Preview Available !
Features
n Internal Ballast Resistor Permits Direct
Connection to Power Plane for Higher Current
and Heat Spreading
n Output Current: 1.1A
n Single Resistor Programs Output Voltage
n 1% Initial Accuracy of SET Pin Current
n Output Adjustable to 0V
n Low Output Noise: 40µVRMS (10Hz to 100kHz)
n Wide Input Voltage Range: 1.2V to 36V
n Low Dropout Voltage: 350mV
n <0.001%/ V Line Regulation
n Minimum Load Current: 0.5mA
n Stable with 2.2µF Minimum Ceramic Output Capacitor
n Current Limit with Foldback and Overtemperature
Protected
n Available in 8-Lead MSOP and 3mm × 3mm DFN
Applications
n High Current All Surface Mount Supply
n High Efficiency Linear Regulator
n Post Regulator for Switching Supplies
n Low Parts Count Variable Voltage Supply
n Low Output Voltage Power Supplies
LT3080-1
Parallelable 1.1A
Adjustable Single Resistor
Low Dropout Regulator
Description
The LT®3080-1 is a 1.1A low dropout linear regulator that
incorporates an internal ballast resistor to allow direct
paralleling of devices without the need for PC board trace
resistors. The internal ballast resistor allows multiple de-
vices to be paralleled directly on a surface mount board
for higher output current and power dissipation while
keeping board layout simple and easy. The device brings
out the collector of the pass transistor to allow low dropout
operation—down to 350mV—when used with multiple
input supplies.
The LT3080-1 is capable of supplying a wide output volt-
age range. A reference current through a single resistor
programs the output voltage to any level between zero
and 36V. The LT3080-1 is stable with 2.2µF of ceramic
capacitance on the output, not requiring additional ESR
as is common with other regulators.
Internal protection includes current limiting and thermal
limiting. The LT3080-1 regulator is offered in the 8-lead
MSOP (with an Exposed Pad for better thermal charac-
teristics) and 3mm × 3mm DFN packages.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and VLDO
and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
Typical Application
Paralleling Regulators
VIN
4.8V TO 28V
IN
VCONTROL
IN
VCONTROL
1µF
LT3080-1
+
–
SET
LT3080-1
25mΩ OUT*
+
–
SET
165k
25mΩ
OUT*
30801 TA01
VOUT
3.3V
2.2A
10µF
*OUTPUTS CAN BE
DIRECTLY MOUNTED
TO POWER PLANE
Offset Voltage Distribution
N = 13250
– 2 –1
0
12
VOS DISTRIBUTION (mV)
30801 TA01b
For more information www.linear.com/LT3080-1
30801fc
1
1 page  
Typical Performance Characteristics
LT3080-1
Dropout Voltage
(Minimum IN Voltage)
400
350
ILOAD = 1.1A
300
250
200 ILOAD = 500mA
150
100 ILOAD = 100mA
50
0
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
30801 G10
Dropout Voltage
(Minimum VCONTROL Pin Voltage)
1.6
TJ = –50°C
1.4
1.2
1.0 TJ = 25°C
0.8
TJ = 125°C
0.6
0.4
0.2
0
0 0.2 0.4 0.6 0.8 1.0 1.2
OUTPUT CURRENT (A)
30801 G11
Dropout Voltage
(Minimum VCONTROL Pin Voltage)
1.6
1.4 ILOAD = 1.1A
1.2
1.0 ILOAD = 1mA
0.8
0.6
0.4
0.2
0
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
30801 G12
Current Limit
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2 VIN = 7V
0 VOUT = 0V
–50 –25 0
25 50 75 100 125 150
TEMPERATURE (°C)
30801 G13
Load Transient Response
150
100
50
0
– 50
–100
1.2
0.9
VIN = VCONTROL = 3V
VOUT = 1.5V
0.6 COUT = 10µF CERAMIC
0.3 CSET = 0.1µF
0
0 5 10 15 20 25 30 35 40 45 50
TIME (µs)
30801 G16
Current Limit
1.6
1.4
TJ = 25°C
1.2
1.0
0.8
0.6
0.4
0.2
0
0 6 12 18 24 30 36*
INPUT-TO-OUTPUT DIFFERENTIAL (V)
*SEE NOTE 9 IN ELECTRICAL
CHARACTERISTICS TABLE
30801 G14
Line Transient Response
75
50
25
0
–25
– 50
6
VOUT = 1.5V
ILOAD = 10mA
COUT = 2.2µF
5
CERAMIC
CSET = 0.1µF
4 CERAMIC
3
2
0 10 20 30 40 50 60 70 80 90 100
TIME (µs)
30801 G17
For more information www.linear.com/LT3080-1
Load Transient Response
60 VOUT = 1.5V
40 CSET = 0.1µF
20 VIN = VCONTROL = 3V
0
–20 COUT = 10µF CERAMIC
– 40 COUT = 2.2µF CERAMIC
400
300
200
100
0
0 5 10 15 20 25 30 35 40 45 50
TIME (µs)
30801 G15
Turn-On Response
5
4
3
2
1
0
2.0
1.5 COUT = 2.2µF CERAMIC
1.0 RSET = 100k
0.5 CSET = 0
0 RLOAD = 1Ω
0 1 2 3 4 5 6 7 8 9 10
TIME (µs)
30801 G18
30801fc
5
5 Page 
LT3080-1
Applications Information
output of 2A. At low output voltage, 1V, this adds 2.5%
regulation. The output can be set 19mV high for lower ab-
solute error ±1.3%. Of course, more than two LT3080-1’s
can be paralleled for even higher output current. They are
spread out on the PC board, spreading the heat. Input
resistors can further spread the heat if the input-to-output
difference is high.
Thermal Performance
In this example, two LT3080-1 3mm × 3mm DFN devices
are mounted on a 1oz copper 4-layer PC board. They are
placed approximately 1.5 inches apart and the board is
mounted vertically for convection cooling. Two tests were
set up to measure the cooling performance and current
sharing of these devices.
The first test was done with approximately 0.7V input-
to-output and 1A per device. This gave a 700 milliwatt
dissipation in each device and a 2A output current. The
temperature rise above ambient is approximately 28°C
and both devices were within plus or minus 1°C. Both
the thermal and electrical sharing of these devices is
excellent. The thermograph in Figure 5 shows the tem-
perature distribution between these devices and the PC
board reaches ambient temperature within about a half
an inch from the devices.
The power is then increased with 1.7V across each de-
vice. This gives 1.7 watts dissipation in each device and
a device temperature of about 90°C, about 65°C above
ambient as shown in Figure 6. Again, the temperature
matching between the devices is within 2°C, showing
excellent tracking between the devices. The board tem-
perature has reached approximately 40°C within about
0.75 inches of each device.
While 90°C is an acceptable operating temperature for
these devices, this is in 25°C ambient. For higher am-
bients, the temperature must be controlled to prevent
device temperature from exceeding 125°C. A three meter
per second airflow across the devices will decrease the
device temperature about 20°C providing a margin for
higher operating ambient temperatures.
Both at low power and relatively high power levels de-
vices can be paralleled for higher output current. Current
sharing and thermal sharing is excellent, showing that
acceptable operation can be had while keeping the peak
temperatures below excessive operating temperatures on
a board. This technique allows higher operating current
linear regulation to be used in systems where it could
never be used before.
Figure 5. Temperature Rise at 700mW Dissipation
Figure 6. Temperature Rise at 1.7W Dissipation
For more information www.linear.com/LT3080-1
30801fc
11
11 Page | ||
| Páginas | Total 24 Páginas | |
| PDF Descargar | [ Datasheet LT3080-1.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LT3080-1 | Parallelable 1.1A Adjustable Single Resistor Low Dropout Regulator | Linear Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |