Overview
The LM2677S-12 from Texas Instruments is a high-efficiency, 5A step-down switching regulator. It is part of the SIMPLE SWITCHER family, designed to provide a complete power supply solution with a minimal number of external components. This regulator is available in fixed output voltages of 3.3V, 5V, and 12V, as well as an adjustable output version. The LM2677S-12 is particularly noted for its high current capability and excellent line and load regulation characteristics, making it suitable for a variety of applications requiring efficient power management.
Key Specifications
| Parameter | Conditions | Typical | Minimum | Maximum | Units |
|---|---|---|---|---|---|
| Supply Voltage | 8 | 40 | V | ||
| Junction Temperature Range (TJ) | -40 | 125 | °C | ||
| Output Voltage (VOUT) | VIN = 15V to 40V, 100mA ≤ IOUT ≤ 5A | 12 | 11.76 | 12.24 | V |
| Efficiency (η) | VIN = 24V, ILOAD = 5A | 92 | % | ||
| Oscillator Frequency (fO) | Measured at Switch Pin | 260 | 225 | 280 | kHz |
| Maximum Duty Cycle | 91 | % | |||
| Feedback Bias Current (IBIAS) | VFEEDBACK = 1.3V | 85 | nA | ||
| ON/OFF Threshold (VON/OFF) | 0.8 | 2.0 | V |
Key Features
- High Efficiency: Achieves efficiency greater than 90% through the use of a low ON-resistance DMOS power switch.
- Wide Input Voltage Range: Operates with input voltages from 8V to 40V.
- Fixed and Adjustable Output Voltages: Available in fixed output voltages of 3.3V, 5V, and 12V, as well as an adjustable output version from 1.2V to 37V.
- External Sync Clock Capability: Allows synchronization with an external clock in the range of 280kHz to 400kHz.
- Low Standby Current: Draws only 50μA when switched off.
- High Current Capability: Capable of driving up to 5A loads.
- Simple Design: Requires a minimum number of external components, making design and implementation straightforward.
Applications
- Efficient System Preregulator for Linear Voltage Regulators: Acts as a high-efficiency preregulator to improve overall system efficiency.
- Battery Chargers: Suitable for battery charging applications due to its high efficiency and current capability.
- Communications and Radio Equipment: Used in communications and radio equipment where synchronized clock frequency is beneficial.
- General Power Supply Needs: Ideal for various power supply needs in electronic systems requiring high efficiency and reliability.
Q & A
- What is the input voltage range of the LM2677S-12?
The input voltage range is from 8V to 40V.
- What are the fixed output voltage options available for the LM2677 series?
The fixed output voltage options are 3.3V, 5V, and 12V.
- What is the maximum current capability of the LM2677S-12?
The LM2677S-12 can drive up to 5A loads.
- What is the typical efficiency of the LM2677S-12?
The typical efficiency is greater than 90%.
- Can the LM2677S-12 be synchronized with an external clock?
Yes, it can be synchronized with an external clock in the range of 280kHz to 400kHz.
- What is the standby current when the LM2677S-12 is switched off?
The standby current is 50μA when switched off.
- What is the operating junction temperature range of the LM2677S-12?
The operating junction temperature range is from -40°C to 125°C.
- How does the LM2677S-12 achieve high efficiency?
It achieves high efficiency through the use of a low ON-resistance DMOS power switch.
- What types of applications is the LM2677S-12 suitable for?
It is suitable for applications such as efficient system preregulators, battery chargers, communications and radio equipment, and general power supply needs.
- How many external components are required for a complete design using the LM2677S-12?
A minimal number of external components are required, making the design straightforward.
