công cụ tìm kiếm bảng dữ liệu linh kiện điện tử
  Vietnamese  ▼
ALLDATASHEET.VN

X  

LM2619ATL bảng dữ liệu(PDF) 11 Page - National Semiconductor (TI)

[Old version datasheet] Texas Instruments acquired National semiconductor.
tên linh kiện LM2619ATL
Giải thích chi tiết về linh kiện  500mA Sub-Miniature Step-Down DC-DC Converter
Download  15 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
nhà sản xuất  NSC [National Semiconductor (TI)]
Trang chủ  http://www.national.com
Logo NSC - National Semiconductor (TI)

LM2619ATL bảng dữ liệu(HTML) 11 Page - National Semiconductor (TI)

Back Button LM2619ATL Datasheet HTML 7Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 8Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 9Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 10Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 11Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 12Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 13Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 14Page - National Semiconductor (TI) LM2619ATL Datasheet HTML 15Page - National Semiconductor (TI)  
Zoom Inzoom in Zoom Outzoom out
 11 / 15 page
background image
Device Information (Continued)
less than the 2.8V minimum operating voltage. The LM2619
is designed for compact portable applications, such as mo-
bile phones. In such applications, the system controller de-
termines power supply sequencing. Although the LM2619 is
typically well behaved at low input voltages, this is not guar-
anteed.
INTERNAL SYNCHRONOUS RECTIFICATION
While in PWM mode, the LM2619 uses an internal NFET as
a synchronous rectifier to reduce rectifier forward voltage
drop and associated power loss. Synchronous rectification
provides a significant improvement in efficiency whenever
the output voltage is relatively low compared to the voltage
drop across an ordinary rectifier diode.
The internal NFET synchronous rectifier is turned on during
the inductor current down slope during the second part of
each cycle. The synchronous rectifier is turned off prior to the
next cycle, or when the inductor current ramps to zero at light
loads. The NFET is designed to conduct through its intrinsic
body diode during transient intervals before it turns on, elimi-
nating the need for an external diode.
CURRENT LIMITING
A current limit feature allows the LM2619 to protect itself and
external components during overload conditions. In PWM
mode cycle-by-cycle current limit is normally used. If an
excessive load pulls the voltage at the feedback pin down to
approximately 0.7V, then the device switches to a timed
current limit mode. In timed current limit mode the internal
P-FET switch is turned off after the current comparator trips
and the beginning of the next cycle is inhibited for 2.5µs to
force the instantaneous inductor current to ramp down to a
safe value. Timed current limit mode prevents the loss of
current control seen in some products when the voltage at
the feedback pin is pulled low in serious overload conditions.
DROPOUT CONSIDERATIONS
The LM2619 can be used to provide fixed output voltages by
using external feedback resistors. The output voltage can be
set from 1.5V to 3.6V. The internal reference voltage for the
error amplifier is 1.5V. In cases where the output voltage is
set higher than 2.5V, the part will go into dropout or 100%
duty cycle when the input voltage gets close to the set output
voltage. Near dropout the on time of the P-FET may exceed
one PWM clock cycle and cause higher ripple on the output
for load currents greater than 450mA. This increased ripple
will exist for a narrow range of input voltages close to the
100% duty cycle and once the input voltage goes down
further the P-FET will be fully on. See Setting the Output
Voltage in the Application Information section for further
details.
In dropout conditions the output voltage is V
IN −IOUT (Rdc +
R
DSON (P)) where Rdc is the series resistance of the inductor
and R
DSON (P) is the on resistance of the PFET.
SOFT-START
The LM2619 has soft start to reduce current inrush during
power-up and startup. This reduces stress on the LM2619
and external components. It also reduces startup transients
on the power source. Soft start is implemented by ramping
up the reference input to the error amplifier of the LM2619 to
gradually increase the output voltage.
THERMAL SHUTDOWN PROTECTION
The LM2619 has a thermal shutdown protection function to
protect itself from short-term misuse and overload condi-
tions. When the junction temperature exceeds 150˚C the
device turns off the output stage and when the temperature
drops below 130˚C it initiates a soft start cycle. Prolonged
operation in thermal shutdown conditions may damage the
device and is considered bad practice.
Load Transient Response
(Circuit in Figure 3)
20057427
FIGURE 8.
Line Transient Response
(Circuit in Figure 3)
20057428
FIGURE 9.
www.national.com
11


Số phần tương tự - LM2619ATL

nhà sản xuấttên linh kiệnbảng dữ liệuGiải thích chi tiết về linh kiện
logo
National Semiconductor ...
LM2619ATL NSC-LM2619ATL Datasheet
844Kb / 15P
   500mA Sub-Miniature Step-Down DC-DC Converter
logo
Texas Instruments
LM2619ATL/NOPB TI1-LM2619ATL/NOPB Datasheet
1Mb / 21P
[Old version datasheet]   500-mA Sub-Miniature Step-Down DC-DC Converter
logo
National Semiconductor ...
LM2619ATLX NSC-LM2619ATLX Datasheet
844Kb / 15P
   500mA Sub-Miniature Step-Down DC-DC Converter
More results

Mô tả tương tự - LM2619ATL

nhà sản xuấttên linh kiệnbảng dữ liệuGiải thích chi tiết về linh kiện
logo
National Semiconductor ...
LM2619 NSC-LM2619 Datasheet
844Kb / 15P
   500mA Sub-Miniature Step-Down DC-DC Converter
LM2619MTC NSC-LM2619MTC Datasheet
799Kb / 16P
   500mA Step-Down DC-DC Converter
logo
Advanced Analogic Techn...
AAT1130 ANALOGICTECH-AAT1130 Datasheet
3Mb / 19P
   2.5MHz 500mA Step-Down DC/DC Converter
logo
Texas Instruments
LM2619 TI1-LM2619_15 Datasheet
1Mb / 21P
[Old version datasheet]   500-mA Sub-Miniature Step-Down DC-DC Converter
logo
Linear Technology
LTC3542 LINER-LTC3542 Datasheet
212Kb / 16P
   500mA, 2.25MHz Synchronous Step-Down DC/DC Converter
logo
HY-LINE Power Component...
P78A1R5 HY-LINE-P78A1R5 Datasheet
327Kb / 2P
   500mA DC-DC Step Down Converter P78A-Series
Rev: 4.08 f
logo
Linear Technology
LTC3542 LINER-LTC3542_15 Datasheet
222Kb / 16P
   500mA, 2.25MHz Synchronous Step-Down DC/DC Converter
logo
Texas Instruments
LM3204 TI1-LM3204_16 Datasheet
950Kb / 24P
[Old version datasheet]   Miniature, Adjustable, Step-Down DC-DC Converter
LM3200 TI1-LM3200 Datasheet
982Kb / 24P
[Old version datasheet]   Miniature, Adjustable, Step-Down DC-DC Converter
LM3262 TI1-LM3262 Datasheet
2Mb / 41P
[Old version datasheet]   Miniature, Adjustable, Step-Down DC-DC Converter
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


bảng dữ liệu tải về

Go To PDF Page


Link URL




Chính sách bảo mật
ALLDATASHEET.VN
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không?  [ DONATE ] 

Alldatasheet là   |   Quảng cáo   |   Liên lạc với chúng tôi   |   Chính sách bảo mật   |   Trao đổi link   |   Tìm kiếm theo nhà sản xuất
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