Overview
The LM2678SX-12/NOPB is a monolithic integrated circuit from Texas Instruments, designed as a step-down (buck) switching regulator. It is part of the SIMPLE SWITCHER® family and is capable of driving up to 5-A loads with excellent line and load regulation characteristics. The regulator offers high efficiency, typically up to 92%, achieved through the use of a low ON-resistance DMOS power switch. It is available in fixed output voltages of 3.3 V, 5 V, and 12 V, as well as an adjustable output version ranging from 1.2 V to 37 V.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Maximum Input Voltage | 40 | V |
| Minimum Input Voltage | 8 | V |
| Maximum Output Current | 5 | A |
| Output Voltage (Fixed Version) | 12 | V |
| Output Voltage Tolerance | ±2% | |
| Operating Junction Temperature Range | -40 to 125 | °C |
| Switch ON-Resistance | 120 mΩ | |
| Fixed Frequency Internal Oscillator | 260 kHz | |
| Standby Current When Switched OFF | 50 µA |
Key Features
- High efficiency up to 92% due to the low ON-resistance DMOS power switch.
- Simple and easy to design using off-the-shelf external components.
- Fixed output voltages of 3.3 V, 5 V, and 12 V, and an adjustable output version from 1.2 V to 37 V.
- Wide input voltage range: 8 V to 40 V.
- 260-kHz fixed frequency internal oscillator.
- Built-in thermal shutdown, current limiting, and ON/OFF control input.
- Low standby current of 50 µA when switched OFF.
- ±2% maximum output tolerance over full line and load conditions.
Applications
- Simple-to-design, high-efficiency step-down switching regulators.
- Efficient system preregulator for linear voltage regulators.
- Battery chargers.
- General power supply applications requiring high current and efficiency.
Q & A
- What is the maximum output current of the LM2678SX-12/NOPB?
The maximum output current is 5 A.
- What are the fixed output voltage options available for the LM2678 series?
The fixed output voltage options are 3.3 V, 5 V, and 12 V, along with an adjustable output version).
- What is the operating junction temperature range of the LM2678SX-12/NOPB?
The operating junction temperature range is -40°C to 125°C).
- What is the efficiency of the LM2678SX-12/NOPB?
The efficiency is up to 92%).
- What is the standby current when the regulator is switched OFF?
The standby current is 50 µA when switched OFF).
- What is the fixed frequency of the internal oscillator?
The fixed frequency of the internal oscillator is 260 kHz).
- Does the LM2678SX-12/NOPB have built-in protection features?
Yes, it has built-in thermal shutdown, current limiting, and an ON/OFF control input).
- What is the output voltage tolerance of the LM2678SX-12/NOPB?
The output voltage tolerance is ±2% over full line and load conditions).
- Can the LM2678SX-12/NOPB be used in battery charger applications?
Yes, it can be used in battery charger applications due to its high efficiency and current capability).
- How can I design a custom circuit using the LM2678?
You can use the WEBENCH® Power Designer tool to create a custom design using the LM2678).
