|
|
PDF LTM8022 Data sheet ( Hoja de datos )
| Número de pieza | LTM8022 | |
| Descripción | 36V DC/DC uModule | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTM8022 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
LTM8022
1A, 36V DC/DC µModule
FEATURES
n Complete Step-Down Switch Mode Power Supply
n Wide Input Voltage Range: 3.6V to 36V
n 0.8V to 10V Output Voltage
n 1A Output Current
n Adjustable Switching Frequency: 200kHz to 2.4MHz
n Current Mode Control
n (e4) RoHS Compliant Package with Gold Pad Finish
n Programmable Soft-Start
n Tiny, Low Profile (11.25mm × 9mm × 2.82mm)
Surface Mount LGA Package
APPLICATIONS
n Automotive Battery Regulation
n Power for Portable Products
n Distributed Supply Regulation
n Industrial Supplies
n Wall Transformer Regulation
DESCRIPTION
The LTM®8022 is a complete 1A, DC/DC step-down power
supply. Included in the package are the switching controller,
power switches, inductor, and all support components.
Operating over an input voltage range of 3.6V to 36V, the
LTM8022 supports an output voltage range of 0.8V to 10V,
and a switching frequency range of 200kHz to 2.4MHz,
each set by a single resistor. Only the bulk input and output
filter capacitors are needed to finish the design.
The low profile package (2.82mm) enables utilization of
unused space on the bottom of PC boards for high density
point of load regulation.
The LTM8022 is packaged in a thermally enhanced, compact
(11.25mm × 9mm) and low profile (2.82mm) overmolded
land grid array (LGA) package suitable for automated
assembly by standard surface mount equipment. The
LTM8022 is RoHS compliant.
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
VIN*
7V TO
36V
7VIN to 36VIN, 5V/1A μModule® Regulator
2.2μF
VIN VOUT
LTM8022
RUN/SS
AUX
SHARE
BIAS
VOUT
5V
1A
4.7μF
PG
RT GND SYNC ADJ
29.4k
93.1k
8022 TA01a
*RUNNING VOLTAGE RANGE. PLEASE REFER TO
APPLICATIONS INFORMATION FOR START-UP DETAILS
Efficiency and Power Loss
100
VIN = 12V
90
80
EFFICIENCY
70
60
50
40
POWER
LOSS
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
30
0.001
0.01 0.1
LOAD CURRENT (A)
0
1
8022 TA01b
8022fd
1
1 page  
LTM8022
TYPICAL PERFORMANCE CHARACTERISTICS (TA = 25°C, unless otherwise noted)
Output Current vs Input Voltage
(Output Short)
3200
3000
2800
2600
2400
2200
2000
1800
1600
0
10 20
30
INPUT VOLTAGE (V)
40
8022 G10
BIAS Quiescent Current
vs Load Current
16
14
12
10 8VOUT
8
5VOUT
6
3.3VOUT
4
2
0
0 200 400 600 800 1000
LOAD CURRENT (mA)
8022 G11
Minimum Required Input Voltage
vs Output Load (8VOUT)
1200
1000
800
600
400
200
0
0
10 20
30
INPUT VOLTAGE (V)
25°C
85°C
40
8022 G13
Minimum Required Input Voltage
vs Output Load (5VOUT)
1200
Minimum Required Input Voltage
vs Output Load (3.3VOUT)
1200
1000
1000
800 800
600 600
400 400
200
0
0
10 20
30
INPUT VOLTAGE (V)
25°C
85°C
40
8022 G14
200
0
0
10 20
30
INPUT VOLTAGE (V)
25°C
85°C
40
8022 G15
Temperature Rise vs Load
(3.3VOUT)
25
20
15
36VIN
10
12VIN
24VIN
5
Temperature Rise vs Load
(5VOUT)
35
30
25
20
36VIN
15
12VIN
10 24VIN
5
Temperature Rise vs Load
(8VOUT)
40
35
30
25
36VIN
24VIN
20
15
12VIN
10
5
0
0 200 400 600 800 1000 1200
LOAD (mA)
8022 G16
0
0 200 400 600 800 1000 1200
LOAD (mA)
8022 G17
0
0 200 400 600 800 1000 1200
LOAD (mA)
8022 G18
8022fd
5
5 Page 
LTM8022
APPLICATIONS INFORMATION
Load Sharing
Two or more LTM8022’s may be paralleled to produce higher
currents. To do this, tie the VIN, VOUT and SHARE pins of
all the paralleled LTM8022’s together. Synchronize the
LTM8022s to avoid beat frequencies if required. To ensure
that paralleled modules start up together, the RUN/SS pins
may be tied together, as well. If the RUN/SS pins are not
tied together, make sure that the same valued soft-start
capacitors are used for each module. An example of two
LTM8022 modules configured for load sharing is given in
the Typical Applications section.
Soft-Start
The RUN/SS pin can be used to soft-start the LTM8022,
reducing the maximum input current during start-up. The
RUN/SS pin is driven through an external RC filter to create
a voltage ramp at this pin. Figure 2 shows the start-up and
shutdown waveforms with the soft-start circuit. By choos-
ing an appropriate RC time constant, the peak start-up
current can be reduced to the current that is required to
regulate the output, with no overshoot. Choose the value
of the resistor so that it can supply at least 20μA when the
RUN/SS pin reaches 2.5V.
Synchronization
The internal oscillator of the LTM8022 can be synchronized
by applying an external 250kHz to 2MHz clock signal to
the SYNC pin. The resistor tied from the RT pin to ground
should be chosen such that the LTM8022 would free run
20% lower than the intended synchronization frequency
(see Frequency Selection section).
When the LTM8022 is synchronized to an external clock
source, Burst Mode operation is disabled. The part will
skip power switching cycles as necessary to maintain
regulation. Ensure that the SYNC pin is not left floating.
Tie it to GND if not used.
Shorted Input Protection
Care needs to be taken in systems where the output will be
held high when the input to the LTM8022 is absent. This
may occur in battery charging applications, or in battery
backup systems where a battery or some other supply is
diode ORed with the LTM8022’s output. If the VIN pin is
allowed to float, and the RUN/SS pin is held high (either
by a logic signal or because it is tied to VIN), then the
LTM8022’s internal circuitry will pull its quiescent current
through its internal power switch. This is fine if your system
can tolerate a few milliamps in this state. If you ground
the RUN/SS pin, the internal switch current will drop to
essentially zero. However, if the VIN pin is grounded while
the output is held high, then parasitic diodes inside the
LTM8022 can pull large currents from the output through
the VIN pin. Figure 3 shows a circuit that will run only when
the input voltage is present and that protects against a
shorted or reversed input.
RUN
15k
RUN/SS
GND
0.22μF
2ms/DIV
IL
0.5A/DIV
VRUN/SS
2V/DIV
VOUT
2V/DIV
8022 F02
Figure 2. To Soft-Start the LTM8022, Add a
Resistor and Capacitor to the RUN/SS Pin
VIN
VIN VOUT
VOUT
AUX
LTM8022
BIAS
RUN/SS
PG
RT GND SYNC ADJ
8022 F03
Figure 3. The Input Diode Prevents a Shorted Input from
Discharging a Back-Up Battery Tied to the Output. It Also
Protects the Circuit From a Reversed Input. The LTM8022
Runs Only When the Input is Present
8022fd
11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet LTM8022.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTM8020 | 36V DC/DC Module | Linear Technology |
| LTM8021 | 500mA Step-Down DC/DC Module | Linear Technology |
| LTM8022 | 36V DC/DC uModule | Linear Technology |
| LTM8023 | 36V DC/DC Module | 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 |