LM2576 SIMPLE SWITCHER® 3A Step-Down Voltage Regulator
LM2576 特性Features
- 3.3V, 5V, 12V, 15V, and adjustable output versions
- Adjustable version output voltage range, 1.23V to 37V (57V for HV version) ±4% max over line and load conditions
- Guaranteed 3A output current
- Wide input voltage range, 40V up to 60V for HV version
- Requires only 4 external components
- 52 kHz fixed frequency internal oscillator
- TTL shutdown capability, low power standby mode
- High efficiency
- Uses readily available standard inductors
- Thermal shutdown and current limit protection
- P+ Product Enhancement tested
LM2576 概述Description
The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output version.
Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator.
The LM2576 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some cases no heat sink is required.
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.
Other features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50 µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.
LM2576 应用Applications
- Simple high-efficiency step-down (buck) regulator
- Efficient pre-regulator for linear regulators
- On-card switching regulators
- Positive to negative converter (Buck-Boost)
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LM2576 功能框图Block Diagram |
LM2576 典型性能Typical Performance |
|---|
LM2576 性能参数Parametrics
| Paramaters / Values | LM2576 | LM25005 | LM25576 | LM2673 | LM2676 | LM2696 | LM5005 | LM2596 | LM2599 |
|---|---|---|---|---|---|---|---|---|---|
| Output Current | 3000 mA | 2500 mA | 3000 mA | 3000 mA | 3000 mA | 3000 mA | 2500 mA | 3000 mA | 3000 mA |
| Input Min Voltage | 4 Volt | 7 Volt | 6 Volt | 15, 8 Volt | 15, 8 Volt | 4.5 Volt | 7 Volt | 4.5, 7, 4.75, 15 Volt | 4.5, 7, 4.75, 15 Volt |
| Input Max Voltage | 40 Volt | 42 Volt | 42 Volt | 40 Volt | 40 Volt | 24 Volt | 75 Volt | 40 Volt | 40 Volt |
| Output Min | 3.3, 1.23, 12, 15, 5 Volt | 1.23 Volt | 1.23 Volt | 3.3, 1.23, 12, 5 Volt | 3.3, 1.23, 12, 5 Volt | 1.254 Volt | 1.23 Volt | 3.3, 1.23, 12, 5 Volt | 3.3, 1.23, 12, 5 Volt |
| Output Max | 3.3, 37, 12, 15, 5 Volt | 37 Volt | 40 Volt | 3.3, 12, 37, 5 Volt | 3.3, 12, 37, 5 Volt | 20 Volt | 70 Volt | 3.3, 37, 12, 5 Volt | 3.3, 37, 12, 5 Volt |
| Frequency Min | 52 kHz | 50 kHz | 50 kHz | 260 kHz | 260 kHz | 100 kHz | 50 kHz | 150 kHz | 150 kHz |
| Frequency Max | 52 kHz | 500 kHz | 1000 kHz | 260 kHz | 260 kHz | 500 kHz | 500 kHz | 150 kHz | 150 kHz |
| Efficiency (peak) | 77, 88, 75 % | 94 % | 91 % | 94, 88, 86 % | 94, 88, 86 % | 90 % | 94 % | 90, 73, 80 % | 90 % |
| On/Off Pin | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes | Yes |
| PowerGood / Error Flag | No | No | No | No | No | Yes | No | No | Yes |
| SoftStart | No | Yes | Yes | Yes | No | Yes | Yes | No | Yes |
| Sync Pin | No | Yes | Yes | No | No | No | Yes | No | No |
| Inverting | Yes | Yes | Yes | Yes | Yes | Yes | Yes | ||
| Flyback | No | No | No | No | No | No | No | No | No |
| RegType | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator |
| Temperature Min | -40 deg C | -40 deg C | -40 deg C | -40 deg C | -40 deg C | -40 deg C | -40 deg C | -40 deg C | -40 deg C |
| Temperature Max | 125 deg C | 125 deg C | 125 deg C | 125 deg C | 125 deg C | 125 deg C | 125 deg C | 125 deg C | 125 deg C |
| Adjustable Output | Yes, No | Yes | Yes | Yes, No | Yes, No | Yes | Yes | Yes, No | Yes, No |
| Adj Switch Frequency | No | Yes | Yes | No | No | Yes | Yes | No | No |
| PWM Mode | Voltage | Current | Current | Voltage with Vin Feedforward | Voltage with Vin Feedforward | Constant on-time | Current | Voltage | Voltage |
| Topology | Buck | Buck, Inverting | Buck | Buck | Buck | Buck | Buck | Buck | Buck |
| Special Features | SIMPLE SWITCHER regulator | 1.5% feedback voltage accuracy, emulated current mode | 1.5% feedback voltage accuracy, emulated current mode | Programmable current limit, 2% output voltage accuracy, SIMPLE SWITCHER regulator | Internal Type 3 compensation, 2% output voltage accuracy, SIMPLE SWITCHER regulator | No compensation required, ultra-fast transient response, thermal shutdown | 1.5% feedback voltage accuracy, emulated current mode | SIMPLE SWITCHER regulator | SIMPLE SWITCHER regulator, error output delay |
| Step-Down | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Multiple Output Capability | No | No | No | No | No | No | No | No | No |
| Output Power | Undefined Watt | Undefined Watt | Undefined Watt | Undefined Watt | Undefined Watt | Undefined Watt | Undefined Watt | ||
| Output Voltage | 3.3, Undefined, 12, 15, 5 Volt | Undefined Volt | 3.3, 12, Undefined, 5 Volt | 3.3, 12, Undefined, 5 Volt | Undefined Volt | 3.3, Undefined, 12, 5 Volt | 3.3, Undefined, 12, 5 Volt | ||
| Output Range | 15V, 5V, 12V, 1.23V to 65V, 3.3V | 1.23V to 37V | 1.23V to 37V | 12V, 1.23V to 37V, 3.3V, 5V | 12V, 1.23V to 37V, 3.3V, 5V | 1.254V to 20V | 1.23V to 70V | 5V, 12V, 1.23V to 37V, 3.3V | 5V, 12V, 1.23V to 37V, 3.3V |
| Switching Frequency | 52 kHz | 500 kHz | 1000 kHz | 260 kHz | 260 kHz | 500 kHz | 500 kHz | 150 kHz | 150 kHz |
| Regulator Family | SIMPLE SWITCHER | SIMPLE SWITCHER | SIMPLE SWITCHER | SIMPLE SWITCHER | Undefined | SIMPLE SWITCHER | SIMPLE SWITCHER | ||
| Synchronous Rectification | No | No | No | No | No | No | No | No | No |
LM2576 芯片订购型号
| Part Number(s) (NSID) |
Top View | Availability | Budgetary Pricing | Pack Size |
|---|---|---|---|---|
| LM2576S-12/NOPB LM2576S-12 |
 TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
 |
| LM2576S-3.3/NOPB LM2576S-3.3 |
TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576S-5.0/NOPB LM2576S-5.0 |
TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576S-ADJ/NOPB LM2576S-ADJ |
TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576SX-3.3/NOPB LM2576SX-3.3 |
TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | reel
of
500
 |
| LM2576SX-5.0/NOPB LM2576SX-5.0 |
TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | reel
of
500
|
| LM2576SX-ADJ/NOPB LM2576SX-ADJ |
TO-263 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | reel
of
500
|
| LM2576T-12/NOPB LM2576T-12 |
 TO-220 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576T-15/NOPB LM2576T-15 |
TO-220 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576T-3.3/NOPB LM2576T-3.3 |
TO-220 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576T-5.0/NOPB LM2576T-5.0 |
TO-220 |
Full production Lead Time: 8 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
| LM2576T-ADJ/NOPB LM2576T-ADJ |
TO-220 |
Full production Lead Time: 12 weeks |
$1.44 each at 1K+ pcs | rail
of
45
|
LM2576 停产Obsolete Versions
| Obsolete Part | Alternate Part or Supplier | Source | Last Time Buy Date |
|---|---|---|---|
| LM2576HVS-15 | LM22676MR-ADJ | NATIONAL SEMICONDUCTOR | 16 Nov 2008 |
| LM2576HVSX-15 | LM22676MRX-ADJ | NATIONAL SEMICONDUCTOR | 16 Nov 2008 |
| LM2576HVT-3.3 | LM22676MR-ADJ | NATIONAL SEMICONDUCTOR | 01 Dec 2009 |
| LM2576S-15 | LM22676MR-ADJ | NATIONAL SEMICONDUCTOR | 16 Nov 2008 |
| LM2576SX-12 | LM22676TJX-ADJ | NATIONAL SEMICONDUCTOR | 01 Dec 2009 |
LM2576 应用技术支持与电子电路设计开发资源下载 Documents
- LM2576 数据手册DataSheet下载. pdf
- LM2576 封装形式尺寸图
- AN-946: Application Note 946 High-Efficiency 3A Battery Chargers Use LM2576 Regulators
- AN-776: Application Note 776 20 Watt Simple Switcher Forward Converter
- AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment
- AN-1229: Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines
- AN-777: Application Note 777 LM2577 Three Output, Isolated Flyback Regulator
- LM2576 绿色环保信息