| Part Number(s) (NSID) |
Top View | Type | Pins | MSL Rating | Peak Reflow | RoHS Status |
CAD Symbols | Models | Package Marking Format |
|---|---|---|---|---|---|---|---|---|---|
| LM2678S-12/NOPB LM2678S-12 |
 |
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-12 |
| LM2678S-3.3/NOPB LM2678S-3.3 |
|
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-3.3 |
| LM2678S-5.0/NOPB LM2678S-5.0 |
|
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-5.0 |
| LM2678S-ADJ/NOPB LM2678S-ADJ |
|
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-ADJ |
| LM2678SD-12/NOPB LM2678SD-12 |
 |
LLP | 14 | 1 1 |
260 260 |
Detail | Download | N/A |
NS UZXYTT S0003BB |
| LM2678SD-3.3/NOPB LM2678SD-3.3 |
|
LLP | 14 | 1 1 |
260 260 |
Detail | Download | N/A |
NS UZXYTT S0003CB |
| LM2678SD-5.0/NOPB LM2678SD-5.0 |
|
LLP | 14 | 1 1 |
260 260 |
Detail | Download | N/A |
NS UZXYTT S0003DB |
| LM2678SD-ADJ/NOPB LM2678SD-ADJ |
|
LLP | 14 | 1 1 |
260 260 |
Detail | Download | N/A |
NS UZXYTT S0003EB |
| LM2678SDX-12 |
|
LLP | 14 | 1 | 260 | Detail | Download | N/A |
NS UZXYTT S0003BB |
| LM2678SDX-3.3 |
|
LLP | 14 | 1 | 260 | Detail | Download | N/A |
NS UZXYTT S0003CB |
| LM2678SDX-5.0/NOPB LM2678SDX-5.0 |
|
LLP | 14 | 1 1 |
260 260 |
Detail | Download | N/A |
NS UZXYTT S0003DB |
| LM2678SDX-ADJ/NOPB LM2678SDX-ADJ |
|
LLP | 14 | 1 1 |
260 260 |
Detail | Download | N/A |
NS UZXYTT S0003EB |
| LM2678SX-12/NOPB |
|
TO-263 | 7 | 3 | 245 | Detail | Download | N/A |
NSUZXYTTE# LM2678 S-12 |
| LM2678SX-3.3/NOPB LM2678SX-3.3 |
|
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-3.3 |
| LM2678SX-5.0/NOPB LM2678SX-5.0 |
|
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-5.0 |
| LM2678SX-ADJ/NOPB LM2678SX-ADJ |
|
TO-263 | 7 | 3 3 |
245 235 |
Detail | Download | N/A |
NSUZXYTTE# LM2678 S-ADJ |
| LM2678T-12/NOPB LM2678T-12 |
 |
TO-220 | 7 | 1 1 |
NA NA |
Detail | Download | N/A |
NSUZXYTTE# LM2678 T-12 |
| LM2678T-3.3/NOPB LM2678T-3.3 |
|
TO-220 | 7 | 1 1 |
NA NA |
Detail | Download | N/A |
NSUZXYTTE# LM2678 T-3.3 |
| LM2678T-5.0/NOPB LM2678T-5.0 |
|
TO-220 | 7 | 1 1 |
NA NA |
Detail | Download | N/A |
NSUZXYTTE# LM2678 T-5.0 |
| LM2678T-ADJ/NOPB LM2678T-ADJ |
|
TO-220 | 7 | 1 1 |
NA NA |
Detail | Download | N/A |
NSUZXYTTE# LM2678 T-ADJ |
PDF
Description
The LM2678 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 5A 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 LM2678 are available from several manufacturers to greatly simplify the design process.
The LM2678 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.
| • | Simple to design, high efficiency (>90%) step-down switching regulators |
| • | Efficient system pre-regulator for linear voltage regulators |
| • | Battery chargers |
| • | Efficiency up to 92% |
| • | Simple and easy to design with (using off-the-shelf external components) |
| • | 120 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 |
Diagrams
Typical Application
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Block Diagram
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Typical Performance 
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