Overview
The LM3478MM, produced by Texas Instruments, is a versatile Low-Side N-Channel MOSFET controller designed for use in switching regulators. It is particularly suited for topologies that require a low-side MOSFET, such as boost, flyback, and SEPIC converters. The device operates with a wide supply voltage range of 2.97 V to 40 V and supports adjustable switching frequencies between 100 kHz and 1 MHz using a single external resistor. This controller is known for its high efficiency, internal soft-start, and current mode operation, which provides superior bandwidth and transient response.
Key Specifications
| Specification | Value |
|---|---|
| Package | 8-lead VSSOP-8 and SOIC-8 |
| Operating Temperature Range | -40°C to 125°C |
| Supply Voltage Range | 2.97 V to 40 V |
| Switching Frequency Range | 100 kHz to 1 MHz |
| Internal Reference Accuracy | ±2.5% (Over Temperature) |
| Peak Current Capability | 1 A |
| Shutdown Current | 10 µA (Over Temperature) |
| Body Size (Nominal) | VSSOP: 3.00 mm x 3.00 mm, SOIC: 4.90 mm x 3.91 mm |
Key Features
- Internal Push-Pull Driver With 1-A Peak Current Capability
- Current Limit and Thermal Shutdown
- Frequency Compensation Optimized With a Capacitor and a Resistor
- Internal Soft Start
- Current Mode Operation
- Undervoltage Lockout With Hysteresis
- Power Saving Shutdown Mode Reducing Total Supply Current to 5 µA
- Adjustable Switching Frequency Between 100 kHz and 1 MHz
- Create a Custom Design Using the LM3478 with the WEBENCH Power Designer
Applications
- Distributed Power Systems
- Battery Chargers
- Offline Power Supplies
- Telecom Power Supplies
- Automotive Power Systems
Q & A
- What is the primary function of the LM3478MM?
The LM3478MM is a Low-Side N-Channel MOSFET controller for switching regulators, suitable for topologies like boost, flyback, and SEPIC converters.
- What is the operating temperature range of the LM3478MM?
The operating temperature range is -40°C to 125°C.
- What is the supply voltage range for the LM3478MM?
The supply voltage range is 2.97 V to 40 V.
- How can the switching frequency of the LM3478MM be adjusted?
The switching frequency can be adjusted between 100 kHz and 1 MHz using a single external resistor.
- What is the peak current capability of the internal push-pull driver?
The peak current capability is 1 A.
- Does the LM3478MM have built-in protection features?
Yes, it includes current limit, thermal shutdown, short-circuit protection, and overvoltage protection.
- What is the purpose of the internal soft-start feature?
The internal soft-start feature limits the inrush current at start-up.
- Can the LM3478MM be used in automotive power systems?
Yes, it is suitable for use in automotive power systems.
- How does the power saving shutdown mode function?
The power saving shutdown mode reduces the total supply current to 5 µA and allows power supply sequencing.
- Can the LM3478MM be designed using the WEBENCH Power Designer?
Yes, it can be used to create custom designs with the WEBENCH Power Designer.
