|
|
PDF LM2651MTCX-3.3 Data sheet ( Hoja de datos )
| Número de pieza | LM2651MTCX-3.3 | |
| Descripción | 1.5A High Efficiency Synchronous Switching Regulator | |
| Fabricantes | National Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LM2651MTCX-3.3 (archivo pdf) en la parte inferior de esta página. Total 10 Páginas | ||
|
No Preview Available !
February 2000
LM2651
1.5A High Efficiency Synchronous Switching Regulator
General Description
The LM2651 switching regulator provides high efficiency
power conversion over a 100:1 load range (1.5A to 15mA).
This feature makes the LM2651 an ideal fit in
battery-powered applications that demand long battery life in
both run and standby modes.
Synchronous rectification is used to achieve up to 97% effi-
ciency. At light loads, the LM2651 enters a low power hyster-
etic or “sleep” mode to keep the efficiency high. In many ap-
plications, the efficiency still exceeds 80% at 15mA load. A
shutdown pin is available to disable the LM2651 and reduce
the supply current to less than 10µA.
The LM2651 contains a patented current sensing circuitry for
current mode control. This feature eliminates the external
current sensing resistor required by other current-mode
DC-DC converters.
The LM2651 has a 300 kHz fixed frequency internal oscilla-
tor. The high oscillator frequency allows the use of extremely
small, low profile components.
A programmable soft-start feature limits current surges from
the input power supply at start up and provides a simple
means of sequencing multiple power supplies.
Other protection features include input undervoltage lockout,
current limiting, and thermal shutdown.
Features
n Ultra high efficiency up to 97%
n High efficiency over a 1.5A to milliamperes load range
n 4V to 14V input voltage range
n 1.8V, 2.5V, 3.3V, or ADJ output voltage
n Internal MOSFET switch with low RDS(on) of 75mΩ
n 300kHz fixed frequency internal oscillator
n 7µA shutdown current
n Patented current sensing for current mode control
n Input undervoltage lockout
n Adjustable soft-start
n Current limit and thermal shutdown
n 16-pin TSSOP package
Applications
n Personal digital assistants (PDAs)
n Computer peripherals
n Battery-powered devices
n Handheld scanners
n High efficiency 5V conversion
Typical Application
DS100925-15
Efficiency vs Load Current
(VIN = 5V, VOUT = 3.3V)
© 2000 National Semiconductor Corporation DS100925
DS100925-1
www.national.com
1 page  
All Output Voltage Versions (Continued)
Specifications in
perature range.
sVtIaNn=da1r0dVtyupnelefsasceotahreerwfoisreTsJp=ec2if5ie˚Cd. and
those
with
boldface
type
apply
over
full
operating
junction
tem-
Symbol
Parameter
Conditions
Typical
Limit
Units
IEA_SOURCE Error Amplifier Source
Current
40 µA
25/15
µA(min)
IEA_SINK
Error Amplifier Sink Current
65 µA
30 µA(min)
VEAH
Error Amplifier Output Swing
Upper Limit
2.70 V
2.50/2.40
V(min)
VEAL
Error Amplifier Output Swing
Lower Limit
1.25 V
1.35/1.50
V(max)
VD
fOSC
Body Diode Voltage
Oscillator Frequency
IDIODE = 1.5A
VIN = 4V
1V
300 kHz
280/255
kHz(min)
330/345
kHz(max)
DMAX
Maximum Duty Cycle
VIN = 4V
95 %
92 %(min)
ISS Soft-Start Current
Voltage at the SS pin = 1.4V
11
µA
7 µA(min)
14 µA(max)
ISHUTDOWN Shutdown Pin Current
Shutdown Pin Pulled Low
2.2 µA
0.8/0.5
µA(min)
3.7/4.0
µA(max)
vSHUTDOWN Shutdown Pin Threshold
Voltage
Falling Edge
0.6 V
0.3 V(min)
0.9 V(max)
TSD Thermal Shutdown
Temperature
165 ˚C
TSD_HYST
Thermal Shutdown
Hysteresis Temperature
25 ˚C
Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Operating ratings indicate conditions for which the device is in-
tended to be functional, but device parameter specifications may not be guaranteed under these conditions. For guaranteed specifications and test conditions, see
the Electrical Characteristics.
Note 2: The maximum allowable power dissipation is calculated by using PDmax = (TJmax − TA)/θJA , where TJmax is the maximum junction temperature, TA is the
ambient temperature, and θJA is the junction-to-ambient thermal resistance of the specified package. The 893 mW rating results from using 150˚C, 25˚C, and
140˚C/W for TJmax, TA, and θJA respectively. A θJA of 140˚C/W represents the worst-case condition of no heat sinking of the 16-pin TSSOP package. Heat sinking
allows the safe dissipation of more power. The Absolute Maximum power dissipation must be derated by 7.14mW per ˚C above 25˚C ambient. The LM2651 actively
limits its junction temperature to about 165˚C.
Note 3: The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
Note 4: Typical numbers are at 25˚C and represent the most likely norm.
Note 5: All limits are guaranteed at room temperature (standard typeface) and at temperature extremes (boldface type ). All room temperature limits are 100%
production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to
calculate Average Outgoing Quality Level (AOQL).
5 www.national.com
5 Page | ||
| Páginas | Total 10 Páginas | |
| PDF Descargar | [ Datasheet LM2651MTCX-3.3.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LM2651MTCX-3.3 | 1.5A High Efficiency Synchronous Switching Regulator | National Semiconductor |
| 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 |