Motor de Búsqueda de Datasheet de Componentes Electrónicos
  Spanish  ▼
ALLDATASHEET.ES

X  

LM2746 Datasheet(PDF) 9 Page - National Semiconductor (TI)

[Old version datasheet] Texas Instruments acquired National semiconductor.
No. de pieza LM2746
Descripción Electrónicos  Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
Download  24 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricante Electrónico  NSC [National Semiconductor (TI)]
Página de inicio  http://www.national.com
Logo NSC - National Semiconductor (TI)

LM2746 Datasheet(HTML) 9 Page - National Semiconductor (TI)

Back Button LM2746 Datasheet HTML 5Page - National Semiconductor (TI) LM2746 Datasheet HTML 6Page - National Semiconductor (TI) LM2746 Datasheet HTML 7Page - National Semiconductor (TI) LM2746 Datasheet HTML 8Page - National Semiconductor (TI) LM2746 Datasheet HTML 9Page - National Semiconductor (TI) LM2746 Datasheet HTML 10Page - National Semiconductor (TI) LM2746 Datasheet HTML 11Page - National Semiconductor (TI) LM2746 Datasheet HTML 12Page - National Semiconductor (TI) LM2746 Datasheet HTML 13Page - National Semiconductor (TI) Next Button
Zoom Inzoom in Zoom Outzoom out
 9 / 24 page
background image
Block Diagram
20147703
Application Information
THEORY OF OPERATION
The LM2746 is a voltage-mode, high-speed synchronous
buck regulator with a PWM control scheme. It is designed for
use in set-top boxes, thin clients, DSL/Cable modems, and
other applications that require high efficiency buck convert-
ers. It has output shutdown (SD), input undervoltage lock-out
(UVLO) mode and power good (PWGD) flag (based on
overvoltage and undervoltage detection). The overvoltage
and undervoltage signals are logically OR’ed to drive the
power good signal and provide a logic signal to the system if
the output voltage goes out of regulation. Current limit is
achieved by sensing the voltage V
DS across the low side
MOSFET.
START UP/SOFT-START
When V
CC exceeds 2.76V and the shutdown pin (SD) sees
a logic high, the soft-start period begins. Then an internal,
fixed 10 µA source begins charging the soft-start capacitor.
During soft-start the voltage on the soft-start capacitor C
SS is
connected internally to the non-inverting input of the error
amplifier. The soft-start period lasts until the voltage on the
soft-start capacitor exceeds the LM2746 reference voltage
of 0.6V. At this point the reference voltage takes over at the
non-inverting error amplifier input. The capacitance of C
SS
determines the length of the soft-start period, and can be
approximated by:
Where C
SS is in µF and tSS is in ms.
During soft start the Power Good flag is forced low and it is
released when the FB pin voltage reaches 70% of 0.6V. At
this point the chip enters normal operation mode, and the
output overvoltage and undervoltage monitoring starts.
NORMAL OPERATION
While in normal operation mode, the LM2746 regulates the
output voltage by controlling the duty cycle of the high side
and low side MOSFETs (see Typical Application Circuit).The
equation governing output voltage is:
The PWM frequency is adjustable between 50 kHz and 1
MHz and is set by an external resistor, R
FADJ, between the
FREQ pin and ground. The resistance needed for a desired
frequency is approximately:
www.national.com
9


Número de pieza similar - LM2746

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
National Semiconductor ...
LM27402 NSC-LM27402 Datasheet
670Kb / 32P
   High Performance Synchronous Buck Controller with DCR Current Sensing
LM27402 NSC-LM27402 Datasheet
167Kb / 4P
   Current Limit Application Circuits Application Circuits
logo
Texas Instruments
LM27402 TI-LM27402 Datasheet
2Mb / 48P
[Old version datasheet]   LM27402 High-Performance Synchronous Buck Controller With DCR Current Sensing
logo
National Semiconductor ...
LM27402MH NSC-LM27402MH Datasheet
670Kb / 32P
   High Performance Synchronous Buck Controller with DCR Current Sensing
logo
Texas Instruments
LM27402MH/NOPB TI-LM27402MH/NOPB Datasheet
2Mb / 48P
[Old version datasheet]   LM27402 High-Performance Synchronous Buck Controller With DCR Current Sensing
More results

Descripción similar - LM2746

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Texas Instruments
LM2743 TI1-LM2743_14 Datasheet
1Mb / 37P
[Old version datasheet]   Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
LM2743 TI-LM2743_15 Datasheet
1Mb / 41P
[Old version datasheet]   LM2743 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
LM2743MTCX TI-LM2743MTCX Datasheet
1Mb / 37P
[Old version datasheet]   LM2743 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
LM2743 TI1-LM2743 Datasheet
1Mb / 41P
[Old version datasheet]   LM2743 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
LM2744 TI1-LM2744 Datasheet
1Mb / 32P
[Old version datasheet]   Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller with External Reference
LM2744 TI-LM2744_15 Datasheet
1Mb / 33P
[Old version datasheet]   Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller with External Reference
logo
National Semiconductor ...
LM2744 NSC-LM2744 Datasheet
663Kb / 22P
   Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller with External Reference
logo
Winbond
W83321S WINBOND-W83321S Datasheet
795Kb / 18P
   N-Channel FET Synchronous Buck Regulator Controller
logo
Nuvoton Technology Corp...
W83320G NUVOTON-W83320G Datasheet
422Kb / 20P
   N-Channel FET Synchronous Buck Regulator Controller
logo
Winbond
W83320S WINBOND-W83320S Datasheet
506Kb / 18P
   N-Channel FET Synchronous Buck Regulator Controller
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24


Datasheet Descarga

Go To PDF Page


Enlace URL




Política de Privacidad
ALLDATASHEET.ES
¿ALLDATASHEET es útil para Ud.?  [ DONATE ] 

Todo acerca de Alldatasheet   |   Publicidad   |   Contáctenos   |   Política de Privacidad   |   Intercambio de Enlaces   |   Lista de Fabricantes
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com