Overview
The LM3481MMX/NOPB, produced by Texas Instruments, is a versatile and high-performance controller designed for use in boost, SEPIC, and flyback converters. This device operates as a low-side N-FET controller, making it suitable for a wide range of switching regulator applications. It features a current mode control architecture, which provides superior bandwidth and transient response, along with cycle-by-cycle current limiting. The LM3481 is packaged in a 10-lead VSSOP, allowing for compact and efficient design solutions.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Supply Voltage | 2.97 | - | 48 | V |
| Switching Frequency Range | 100 kHz | - | 1 MHz | - |
| Peak Driver Output Current | - | - | 1 A | - |
| Internal Reference Voltage | - | 1.275 | - | V |
| Shutdown Current | - | - | 10 µA | - |
| Junction Temperature Range | -40 | - | 125 | °C |
| Package Type | - | - | 10-Lead VSSOP | - |
Key Features
- Internal push-pull driver with 1A peak current capability
- Current limit and thermal shutdown protection
- Frequency compensation optimized with a capacitor and a resistor
- Internal soft start to limit inrush current at start-up
- Current mode operation with adjustable undervoltage lockout and hysteresis
- Pulse skipping at light loads for improved efficiency
- Overvoltage protection (OVP) sensed at the feedback pin
- Slope compensation to prevent instability in duty cycles greater than 50%
- Adjustable and synchronizable clock frequency between 100 kHz and 1 MHz
Applications
- Boost converters for audio amplifiers in portable speakers
- Wide input boost, SEPIC, and flyback power modules
- Isolated supply (flyback) applications
- Battery-powered boost, SEPIC, and flyback converters
Q & A
- What is the supply voltage range of the LM3481?
The supply voltage range of the LM3481 is from 2.97V to 48V.
- What is the switching frequency range of the LM3481?
The switching frequency range is adjustable between 100 kHz and 1 MHz.
- What type of control architecture does the LM3481 use?
The LM3481 uses a current mode control architecture.
- What are the key protection features of the LM3481?
The key protection features include current limit, thermal shutdown, and overvoltage protection.
- How does the LM3481 handle light load conditions?
The LM3481 uses pulse skipping at light loads to improve efficiency.
- What is the purpose of the internal soft start feature?
The internal soft start feature limits the inrush current at start-up.
- Can the clock frequency of the LM3481 be synchronized to an external clock?
Yes, the clock frequency can be synchronized to an external clock.
- What is the typical shutdown current of the LM3481?
The typical shutdown current is 10 µA.
- What is the package type of the LM3481?
The LM3481 is packaged in a 10-lead VSSOP.
- What are some common applications of the LM3481?
Common applications include boost converters for audio amplifiers, wide input boost, SEPIC, and flyback power modules, and isolated supply applications.
