Overview
The LM22679TJ-ADJ/NOPB is a high-performance step-down (buck) voltage regulator from Texas Instruments, part of their SIMPLE SWITCHER® family. This regulator is designed to provide an efficient and reliable solution for a wide range of applications requiring high voltage and current capabilities. It features a voltage mode constant frequency PWM architecture, which allows for excellent line and load regulation along with high efficiency (> 90%). The device incorporates a 42-V N-channel MOSFET switch that can deliver up to 5 A of load current, making it suitable for various industrial, test and measurement, and general-purpose power supply needs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Voltage Range | 4.5 | 42 | V | |
| Output Voltage (ADJ Version) | 1.285 | V | ||
| Output Voltage (Fixed 5V Version) | 4.925 | 5.0 | 5.075 | V |
| Output Current | 5 | A | ||
| Switching Frequency | 400 | 500 | 600 | kHz |
| Operating Junction Temperature Range | -40 | 125 | °C | |
| Feedback Reference Accuracy | ±1.5% | |||
| Current Limit | 6.0 | 7.1 | 8.4 | A |
| Thermal Shutdown Threshold | 150 | °C |
Key Features
- Wide Input Voltage Range: 4.5 V to 42 V, making it versatile for various applications.
- High Efficiency: Greater than 90%, ensuring minimal heat generation and power loss.
- Adjustable Output Voltage: The ADJ version allows output voltages as low as 1.285 V, while the fixed version is set to 5 V.
- Internal Loop Compensation: Optimized for stable operation with low-ESR ceramic capacitors.
- Adjustable Soft-Start: Allows gradual start-up to reduce start-up stresses, adjustable via an external capacitor.
- Adjustable Current Limit: Programmable with a single external resistor to optimize current limits.
- Integrated Bootstrap Diode: Simplifies the design by eliminating the need for an external bootstrap diode.
- Thermal Shutdown Protection: Protects the device from overheating by shutting down at approximately 150°C.
- AEC-Q100 Qualified (LM22679-Q1): Suitable for automotive applications.
Applications
- Industrial Distributed Power Applications: Suitable for high-voltage and high-current industrial power supplies.
- Test and Measurement Equipment: Reliable and efficient power supply for test and measurement devices.
- Appliances: Used in various household and commercial appliances requiring stable and efficient power supply.
- General-Purpose Wide VIN Applications: Versatile enough to be used in any application requiring a wide input voltage range.
Q & A
- What is the input voltage range of the LM22679?
The input voltage range is from 4.5 V to 42 V.
- What are the output voltage options for the LM22679?
The output voltage can be either fixed at 5 V or adjustable down to 1.285 V.
- What is the maximum output current of the LM22679?
The maximum output current is 5 A.
- What is the switching frequency of the LM22679?
The switching frequency is 500 kHz.
- How can the soft-start time be adjusted?
The soft-start time can be adjusted by using an external capacitor connected to the SS pin.
- Can the current limit be adjusted?
Yes, the current limit can be adjusted using a single external resistor connected to the IADJ pin.
- What type of diode is recommended for use with the LM22679?
A Schottky-type power diode is recommended due to its ideal reverse recovery characteristics and low forward voltage drop.
- Is the LM22679-Q1 version suitable for automotive applications?
Yes, the LM22679-Q1 is AEC-Q100 qualified and suitable for automotive applications.
- What is the thermal shutdown threshold of the LM22679?
The thermal shutdown threshold is approximately 150°C.
- How can the output voltage be set for voltages greater than 5 V?
For output voltages greater than 5 V, an external resistor divider can be used with either the -ADJ or -5.0 options.
