LM2676 SIMPLE SWITCHER High Efficiency 3A Step-Down Voltage Regulator
LM2676 特性Features
- Efficiency up to 94%
- Simple and easy to design with (using off-the-shelf external components)
- 150 mΩ DMOS output switch
- 3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V ) versions
- 50μA standby current when switched OFF
- ±2%maximum output tolerance over full line and load conditions
- Wide input voltage range: 8V to 40V
- 260 KHz fixed frequency internal oscillator
- −40 to +125°C operating junction temperature range
LM2676 概述Description
The LM2676 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 3A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance DMOS power switch. The series consists of fixed output voltages of 3.3V, 5V and 12V and an adjustable output version.
The SIMPLE SWITCHER concept provides for a complete design using a minimum number of external components. A high fixed frequency oscillator (260KHz) allows the use of physically smaller sized components. A family of standard inductors for use with the LM2676 are available from several manufacturers to greatly simplify the design process.
The LM2676 series also has built in thermal shutdown, current limiting and an ON/OFF control input that can power down the regulator to a low 50μA quiescent current standby condition. The output voltage is guaranteed to a ±2% tolerance. The clock frequency is controlled to within a ±11% tolerance.
LM2676 应用领域Applications
- Simple to design, high efficiency (>90%) step-down switching regulators
- Efficient system pre-regulator for linear voltage regulators
- Battery chargers
LM2676 典型性能Typical Application
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LM2676 性能参数Parametrics
| Paramaters / Values | LM2676 | LM22676 | LM25576 | LM5576 |
|---|---|---|---|---|
| Output Current | 3000 mA | 3000 mA | 3000 mA | 3000 mA |
| Input Min Voltage | 15, 8 Volt | 4.5 Volt | 6 Volt | 6 Volt |
| Input Max Voltage | 40 Volt | 42 Volt | 42 Volt | 75 Volt |
| Output Min | 3.3, 1.23, 12, 5 Volt | 1.285 Volt | 1.23 Volt | 1.23 Volt |
| Output Max | 3.3, 12, 37, 5 Volt | 40 Volt | 70 Volt | |
| Frequency Min | 260 kHz | 50 kHz | 50 kHz | |
| Frequency Max | 260 kHz | 1000 kHz | 500 kHz | |
| Efficiency (peak) | 94, 88, 86 % | 92 % | 91 % | 88 % |
| On/Off Pin | Yes | Yes | Yes | Yes |
| PowerGood / Error Flag | No | No | No | No |
| SoftStart | No | No | Yes | Yes |
| Sync Pin | No | No | Yes | Yes |
| Flyback | No | No | No | No |
| RegType | Switching Regulator | Switching Regulator | Switching Regulator | Switching Regulator |
| Temperature Min | -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 |
| Adjustable Output | Yes, No | Yes | Yes | Yes |
| Adj Switch Frequency | No | No | Yes | Yes |
| PWM Mode | Voltage with Vin Feedforward | Voltage Mode Control | Current | Current |
| Topology | Buck | Buck | Buck | Buck |
| Special Features | Internal Type 3 compensation, 2% output voltage accuracy, SIMPLE SWITCHER regulator | 500 kHz Switching Frequency | 1.5% feedback voltage accuracy, emulated current mode | 1.5% feedback voltage accuracy, emulated current mode |
| Step-Down | Yes | Yes | Yes | Yes |
| Multiple Output Capability | No | No | No | No |
| Output Power | Undefined Watt | Undefined Watt | Undefined Watt | |
| Output Voltage | 3.3, 12, Undefined, 5 Volt | Undefined Volt | Undefined Volt | |
| Output Range | 12V, 1.23V to 37V, 3.3V, 5V | 1.23V to 37V | 1.23V to 70V | |
| Switching Frequency | 260 kHz | 500 kHz | 1000 kHz | 500 kHz |
| Regulator Family | SIMPLE SWITCHER | SIMPLE SWITCHER | SIMPLE SWITCHER | SIMPLE SWITCHER |
| Synchronous Rectification | No | No | No | No |
LM2676 芯片订购型号
| Part Number(s) (NSID) | Top View | Availability | Budgetary Pricing | Pack Size |
|---|---|---|---|---|
| LM2676S-12/NOPB LM2676S-12 |
 TO-263 |
Full production Lead Time: 16 weeks |
$1.92 each at 1K+ pcs | reel of 45
 |
| LM2676S-3.3/NOPB LM2676S-3.3 |
TO-263 |
Full production Lead Time: 16 weeks |
$1.92 each at 1K+ pcs | reel of 45
|
| LM2676S-5.0/NOPB LM2676S-5.0 |
TO-263 |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel of 45
|
| LM2676S-ADJ/NOPB LM2676S-ADJ |
TO-263 |
Full production Lead Time: 14 weeks |
$1.92 each at 1K+ pcs | reel of 45
|
| LM2676SD-12/NOPB LM2676SD-12 |
 LLP |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel of 250
 |
| LM2676SD-3.3/NOPB LM2676SD-3.3 |
LLP |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel of 250
|
| LM2676SD-5.0/NOPB LM2676SD-5.0 |
LLP |
Full production Lead Time: 12 weeks |
$1.92 each at 1K+ pcs | reel of 250
|
| LM2676SD-ADJ/NOPB LM2676SD-ADJ |
LLP |
Full production Lead Time: 14 weeks |
$1.92 each at 1K+ pcs | reel of 250
|
| LM2676SDX-12/NOPB LM2676SDX-12 |
LLP |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel of 2500
|
| LM2676SDX-3.3/NOPB | LLP |
Full production Lead Time: 16 weeks |
$1.92 each at 1K+ pcs | reel of 2500
|
| LM2676SDX-5.0/NOPB LM2676SDX-5.0 |
LLP |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel of 2500
|
| LM2676SDX-ADJ/NOPB LM2676SDX-ADJ |
LLP |
Full production Lead Time: 14 weeks |
$1.92 each at 1K+ pcs | reel of 2500
|
| LM2676SX-12/NOPB LM2676SX-12 |
TO-263 |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel of 500
|
| LM2676SX-3.3/NOPB LM2676SX-3.3 |
TO-263 |
Full production Lead Time: 10 weeks |
$1.92 each at 1K+ pcs | reel of 500
|
| LM2676SX-5.0/NOPB LM2676SX-5.0 |
TO-263 |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | reel
of
500
|
| LM2676SX-ADJ/NOPB LM2676SX-ADJ |
TO-263 |
Full production Lead Time: 10 weeks |
$1.92 each at 1K+ pcs | reel
of
500
|
| LM2676T-12/NOPB LM2676T-12 |
 TO-220 |
Full production Lead Time: 16 weeks |
$1.92 each at 1K+ pcs | rail
of
45
|
| LM2676T-3.3/NOPB LM2676T-3.3 |
TO-220 |
Full production Lead Time: 6 weeks |
$1.92 each at 1K+ pcs | rail
of
45
|
| LM2676T-5.0/NOPB LM2676T-5.0 |
TO-220 |
Full production Lead Time: 16 weeks |
$1.92 each at 1K+ pcs | rail
of
45
|
| LM2676T-ADJ/NOPB LM2676T-ADJ |
TO-220 |
Full production Lead Time: 16 weeks |
$1.92 each at 1K+ pcs | rail
of
45
|
LM2676 停产Obsolete Versions
| Obsolete Part | Alternate Part or Supplier | Source | Last Time Buy Date |
| LM2676D-12 | NONE | NONE | 30-Jan-04 |
| LM2676LD-3.3 | NONE | NONE | 30-Jan-04 |
| LM2676LD-5.0 | NONE | NONE | 30-Jan-04 |
| LM2676LD-ADJ | NONE | NONE | 30-Jan-04 |
| LM2676LDX-12 | NONE | NONE | 30-Jan-04 |
| LM2676LDX-3.3 | NONE | NONE | 30-Jan-04 |
| LM2676LDX-5.0 | NONE | NONE | 30-Jan-04 |
| LM2676LDX-ADJ | NONE | NONE | 30-Jan-04 |
| LM2676S-5.0EP | NONE | NATIONAL SEMICONDUCTOR | 16-Nov-08 |
LM2676 应用技术支持与电子电路设计开发资源下载 Documents
- LM2676 数据手册DataSheet下载. pdf
- LM2676 封装形式尺寸图
- AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment
- AN-1135: Application Note 1135 LM267X 3A, 5A Evaluation Boards
- AN-1157: Application Note 1157 Positive to Negative Buck‐Boost Converter Using LM267X SIMPLE SWITCHER® Regulators
- AN-1120: Application Note 1120 LM2676-5.0EVAL 1 Amp Step-Down High-Efficiency SIMPLE SWITCHER Evaluation Board
- AN-1229: Application Note 1229 SIMPLE SWITCHER PCB Layout Guidelines