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LM2576のメーカーはHTCです、この部品の機能は「Step-Down Switching Regulator」です。 |
部品番号 | LM2576 |
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部品説明 | Step-Down Switching Regulator | ||
メーカ | HTC | ||
ロゴ | |||
このページの下部にプレビューとLM2576ダウンロード(pdfファイル)リンクがあります。 Total 11 pages
3A, 52kHz, Step-Down Switching Regulator
LM2576
FEATURES
z 3.3V, 5.0V, 12V and Adjustable Output Versions
z Adjustable Version Output Voltage Range, 1.23 to 37V
+/- 4% AG10Maximum Over Line and Load Conditions
z Guaranteed 3.0A Output Current
z Wide Input Voltage Range
z Requires Only 4 External Components
z 52kHz Fixed Frequency Internal Oscillator
z TTL Shutdown Capability, Low Power Standby Mode
z High Efficiency
z Uses Readily Available Standard Inductors
z Thermal Shutdown and Current Limit Protection
z Moisture Sensitivity Level 3 for SMD packages
SOP8-PP PKG
TO-220 PKG
TO-263 PKG
APPLICATION
z Simple High-Efficiency Step-Down(Buck) Regulator
z Efficient Pre-Regulator for Linear Regulators
z On-Card Switching Regulators
z Positive to Negative Converter(Buck-Boost)
z Negative Step-Up Converters
z Power Supply for Battery Chargers
ORDERING INFORMATION
Device
Marking
LM2576DP-X.X
LM2576-X.X
LM2576T-X.X
LM2576-X.X
LM2576R-X.X
LM2576-X.X
Package
SOP8-PP
TO-220
TO-263
DESCRIPTION
The LM2576 series of regulators are monolithic integrated circuits ideally suited for easy and convenient
design of a step-down switching regulator (buck converter).
All circuits of this series are capable of driving a 3.0A load with excellent line and load regulation. These
devices are available in fixed output voltages of 3.3V, 5.0V, 12V and an adjustable output version.
These regulators were designed to minimize the number of external components to simplify the power supply
design. Standard series of inductors optimized for use with the LM2576 are offered by several different inductor
manufacturers.
Since the LM2576 converter is a switch-mode power supply, its efficiency is significantly higher in comparison
with popular three-terminal linear regulators, especially with higher input voltages.
In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced
dramatically. A standard series of inductors optimized for use with the LM2576 are available from several
different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. The LM2576
features include a guaranteed +/- 4% tolerance on output voltage within specified input voltages and output
load conditions, and +/-10% on the oscillator frequency (+/- 2% over 0˚C to 125˚C).
External shutdown is included, featuring 80㎂(typical) standby current. The output switch includes cycle-
bycycle current limiting, as well as thermal shutdown for full protection under fault conditions.
Dec 2011 – Rev. 1.3
-1 -
HTC
1 Page 3A, 52kHz, Step-Down Switching Regulator
PIN CONFIGURATION
VIN 1
VOUT 2
FEEDBACK 3
ON/OFF 4
Exposed
PAD
8 N.C
7 N.C
6 GND
5 N.C.
SOP8-PP
TO220-5L
LM2576
TO263-5L
PIN DESCRIPTION
Package
TO-220 5L
TO-263 5L
SOP8-PP
Symbol
Description
This pin is the positive input supply for the LM2576 step–down
switching regulator.
1 1 VIN In order to minimize voltage transients and to supply the switching
currents needed by the regulator, a suitable input bypass capacitor
must be present. (Cin in Figure 1).
This is the emitter of the internal switch. The saturation voltage
2
2
VOUT
VSAT of this output switch is typically 1.5V. It should be kept in mind
that the PCB area connected to this pin should be kept to a
minimum in order to minimize coupling to sensitive circuitry.
3
6
GND
Circuit ground pin. See the information about the printed circuit
board layout.
This pin senses regulated output voltage to complete the feedback
loop.
The signal is divided by the internal resistor divider network R2, R1
4
3
FEEDBACK
and applied to the non–inverting input of the internal error amplifier.
In the adjustable version of the LM2576 switching regulator this pin
is the direct input of the error amplifier and the resistor network R2,
R1 is connected externally to allow programming of the output
voltage.
It allows the switching regulator circuit to be shutdown using logic
level signals, thus dropping the total input supply current to
approximately 80uA.
5 4 ON/OFF The threshold voltage is typically 1.4V. Applying a voltage above
this value (up to +Vin) shuts the regulator off. If the voltage applied
to this pin is lower than 1.4V or if this pin is left open, the regulator
will be in the "on" condition
-
5, 7, 8
N.C.
No Connect.
* Exposed Pad of SOP8-PP package should be externally connected to GND.
Dec 2011 – Rev. 1.3
-3 -
HTC
3Pages 3A, 52kHz, Step-Down Switching Regulator
LM2576
ELECTRICAL CHARACTERISTICS / SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 15)
(Unless otherwise specified, Vin = 12V for the 3.3V, 5.0V, and Adjustable version, Vin = 25V for the 12V version.
ILoad = 500 mA. For typical values TJ = 25°C, for min/max values TJ is the operating junction temperature range
that applies [Note 2], unless otherwise noted.)
Characteristics
LM2576-3.3V ([Note 1] Test Circuit Figure 2)
Output Voltage (Vin = 12V, ILOAD=0.5A, TJ=25℃)
Output Voltage (6.0V≤Vin≤40V, 0.5A≤ILOAD≤3.0A
TJ=25℃
TJ= -40℃ ~ +125℃
Efficiency (Vin=12V, ILOAD=3.0A)
Symbol
Vout
Vout
η
Min TYP Max Unit
3.234 3.3 3.366 V
3.168 3.3 3.432 V
3.135 - 3.465
- 75 - %
LM2576-5.0V ([Note 1] Test Circuit Figure 2)
Output Voltage (Vin = 12V, ILOAD=0.5A, TJ=25℃)
Output Voltage (8.0V≤Vin≤40V, 0.5A≤ILOAD≤3.0A
TJ=25℃
TJ= -40℃ ~ +125℃
Efficiency (Vin=12V, ILOAD=3.0A)
Vout
Vout
η
4.9 5.0 5.1 V
4.8 5.0 5.2 V
4.75 - 5.25
- 77 - %
LM2576-12V ([Note 1] Test Circuit Figure 2)
Output Voltage (Vin = 25V, ILOAD=0.5A, TJ=25℃)
Output Voltage (15V≤Vin≤40V, 0.5A≤ILOAD≤3.0A
TJ=25℃
TJ= -40℃ ~ +125℃
Efficiency (Vin=25V, ILOAD=3.0A)
Vout
Vout
η
11.76 12 12.24 V
11.52 12 12.48 V
11.4 - 12.6
- 88 - %
LM2576-ADJ ([Note 1] Test Circuit Figure 2)
Feedback Voltage (Vin=12V, ILOAD=0.5A, TJ=25℃)
Feedback Voltage (8.0V≤Vin≤40V, 0.5A≤ILOAD≤3.0A, Vout=5.0V)
TJ=25℃
TJ= -40℃ ~ +125℃
Efficiency (Vin=12V, ILOAD=3.0A, Vout=5.0V)
Vout
Vout
η
1.217
1.193
1.18
-
1.23
1.23
-
77
1.243
1.267
1.28
-
V
V
%
1. External components such as the catch diode, inductor, input and output capacitors can affect switching
regulator system performance.
When the LM2576 is used as shown in the Figure 15 test circuit, system performance will be as shown in
system parameters section.
2. Tested junction temperature range for the LM2576: Tlow = –40°C Thigh = +125°C
Dec 2011 – Rev. 1.3
-6 -
HTC
6 Page | |||
ページ | 合計 : 11 ページ | ||
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PDF ダウンロード | [ LM2576 データシート.PDF ] |
データシートを活用すると、その部品の主な機能と仕様を詳しく理解できます。 ピン構成、電気的特性、動作パラメータ、性能を確認してください。 |
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