Overview
The LM2676SX-12/NOPB, produced by Texas Instruments, is a high-efficiency step-down (buck) switching regulator. This monolithic integrated circuit provides all the active functions necessary for a step-down voltage regulator, making it a versatile and efficient power management solution. The LM2676 series is designed to drive loads up to 3 A with excellent line and load regulation characteristics. It features a low ON-resistance DMOS power switch, which contributes to its high efficiency of over 90%.
The device is available in fixed output voltages of 3.3 V, 5 V, and 12 V, as well as an adjustable output version. The SIMPLE SWITCHER® concept allows for a complete design using a minimum number of external components, simplifying the design process. The regulator includes built-in thermal shutdown, current limiting, and an ON/OFF control input, enabling it to power down to a low 50-µA quiescent current standby condition.
Key Specifications
| Parameter | Test Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Input Supply Voltage | 8 | 40 | V | ||
| Output Voltage (12 V Version) | VIN = 15 V to 40 V, 100 mA ≤ IOUT ≤ 5 A | 11.76 | 12 | 12.24 | V |
| Efficiency (12 V Version) | VIN = 24 V, ILOAD = 5 A | 94% | % | ||
| Quiescent Current | VFEEDBACK = 15 V for 12-V version | 4.2 | 6 | mA | |
| Standby Quiescent Current | ON/OFF pin = 0 V | 50 | 100 | 150 | µA |
| Current Limit | 3.8 | 4.5 | 5.25 | A | |
| Switch ON-Resistance | ISWITCH = 5 A | 0.15 | 0.17 | 0.29 | Ω |
| Oscillator Frequency | 225 | 260 | 280 | kHz | |
| Operating Junction Temperature | -40 | 125 | °C |
Key Features
- High efficiency up to 94% due to the use of a low ON-resistance DMOS power switch.
- Simple and easy to design with, using off-the-shelf external components.
- Fixed output voltages of 3.3 V, 5 V, and 12 V, as well as an adjustable output version (1.2 V to 37 V).
- Wide input voltage range: 8 V to 40 V.
- 260-kHz fixed frequency internal oscillator, allowing the use of physically smaller sized components.
- 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.
- High current capability up to 3 A.
Applications
- Communication modules
- Electricity meters
- Calling button operating panels
- Motor drives
Q & A
- What is the maximum input voltage for the LM2676SX-12/NOPB?
The maximum input voltage is 40 V.
- What are the fixed output voltage options available for the LM2676 series?
The fixed output voltage options are 3.3 V, 5 V, and 12 V, along with an adjustable output version.
- What is the typical efficiency of the LM2676SX-12/NOPB at full load?
The typical efficiency is up to 94%.
- How does the ON/OFF control input work on the LM2676SX-12/NOPB?
The ON/OFF input allows the regulator to be turned OFF by connecting it to ground or any voltage less than 0.8 V, reducing the current drain to 50 µA.
- What is the operating junction temperature range for the LM2676SX-12/NOPB?
The operating junction temperature range is from -40°C to 125°C.
- What is the quiescent current when the regulator is in standby mode?
The standby quiescent current is 50 µA.
- What is the maximum current limit for the LM2676SX-12/NOPB?
The maximum current limit is 5.25 A.
- What is the oscillator frequency of the LM2676SX-12/NOPB?
The oscillator frequency is fixed at 260 kHz.
- How does the thermal shutdown feature work?
The device includes built-in thermal shutdown to protect against overheating, automatically shutting down the regulator when the junction temperature exceeds a certain threshold.
- What are some common applications for the LM2676SX-12/NOPB?
Common applications include communication modules, electricity meters, calling button operating panels, and motor drives.
