Overview
The LM2678SX-ADJ is part of the SIMPLE SWITCHER® family of power converters, designed to provide all the active functions for a step-down switching regulator. This monolithic integrated circuit can drive up to 5-A loads with excellent line and load regulation characteristics. It is known for its high efficiency, achieved through the use of a low ON-resistance DMOS power switch.
Key Specifications
| Parameter | Test Conditions | Typical | Minimum | Maximum | Unit |
|---|---|---|---|---|---|
| Output Voltage (Adjustable) | VIN = 8 V to 40 V, 100 mA ≤ IOUT ≤ 5 A | 1.2 to 37 | 1.2 | 37 | V |
| Efficiency | VIN = 12 V, ILOAD = 5 A | 84% | 82% | 92% | % |
| Switch ON-Resistance | ISWITCH = 5 A, TJ = 25°C | 0.12 | 0.10 | 0.14 | Ω |
| Input Voltage Range | 8 | 40 | V | ||
| Oscillator Frequency | TJ = 25°C | 260 kHz | 225 kHz | 280 kHz | kHz |
| Operating Junction Temperature Range | -40 | 125 | °C | ||
| Standby Quiescent Current | ON/OFF pin = 0 V, TJ = 25°C | 50 μA | 50 μA | 150 μA | μA |
Key Features
- High Efficiency: Up to 92% efficiency, achieved through the use of a low ON-resistance DMOS power switch.
- Simple Design: Easy to design using off-the-shelf external components.
- Fixed and Adjustable Output: Available in fixed output voltages of 3.3 V, 5 V, and 12 V, and an adjustable output version from 1.2 V to 37 V.
- Low Standby Current: 50-μA quiescent current when switched off.
- Wide Input Voltage Range: Operates with input voltages from 8 V to 40 V.
- Fixed Frequency Oscillator: 260-kHz fixed frequency internal oscillator.
- Thermal Protection: Built-in thermal shutdown and current limiting.
- ON/OFF Control: ON/OFF control input to power down the regulator to a low quiescent current standby condition.
Applications
- Simple-to-Design, High Efficiency Step-Down Switching Regulators: Ideal for applications requiring high current capability and efficient operation.
- Efficient System Preregulator for Linear Voltage Regulators: Can be used as a preregulator to improve overall system efficiency.
- Battery Chargers: Suitable for battery charging applications due to its high efficiency and adjustable output.
Q & A
- Q: What is the maximum output current of the LM2678SX-ADJ?
A: The LM2678SX-ADJ can drive up to 5-A loads. - Q: What are the fixed output voltage options available for the LM2678?
A: The fixed output voltage options are 3.3 V, 5 V, and 12 V. - Q: What is the adjustable output voltage range of the LM2678SX-ADJ?
A: The adjustable output voltage range is from 1.2 V to 37 V. - Q: What is the typical efficiency of the LM2678SX-ADJ?
A: The typical efficiency is up to 92%. - Q: What is the input voltage range for the LM2678SX-ADJ?
A: The input voltage range is from 8 V to 40 V. - Q: How does the ON/OFF control work on the LM2678SX-ADJ?
A: The ON/OFF control input can power down the regulator to a low 50-μA quiescent current standby condition by connecting the pin to ground or any voltage less than 0.8 V. - Q: What is the oscillator frequency of the LM2678SX-ADJ?
A: The oscillator frequency is 260 kHz. - Q: Does the LM2678SX-ADJ have built-in thermal protection?
A: Yes, it has built-in thermal shutdown and current limiting. - Q: What is the standby quiescent current of the LM2678SX-ADJ when switched off?
A: The standby quiescent current is 50 μA. - Q: Can the LM2678SX-ADJ be used in battery charging applications?
A: Yes, it is suitable for battery charging applications due to its high efficiency and adjustable output.
