Overview
The LM25576MHX-NS is a 42V, 3A step-down switching regulator produced by National Semiconductor, now part of Texas Instruments. This SIMPLE SWITCHER® buck regulator is designed to be easy to use, allowing design engineers to create robust power supplies with a minimal set of components. It operates with an input voltage range of 6V to 42V and delivers 3A of continuous output current. The regulator features an integrated 170mΩ N-Channel MOSFET and utilizes an Emulated Current Mode architecture, providing inherent line regulation, tight load transient response, and ease of loop compensation.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VIN to GND | - | - | 45 | V |
| BST to GND | - | - | 60 | V |
| SW to GND (Steady State) | -1.5 | - | - | V |
| SD, VCC to GND | - | - | 14 | V |
| Operating Frequency | 50 kHz | - | 1 MHz | - |
| Output Current | - | - | 3 A | - |
| Output Voltage Range | 1.225 V | - | - | - |
| Feedback Reference Accuracy | - | 1.5% | - | - |
| Thermal Shutdown Threshold | - | - | 165 °C | - |
| Package Type | - | - | HTSSOP-20EP (Exposed Pad) | - |
Key Features
- Integrated 42V, 170mΩ N-Channel MOSFET
- Ultra-wide input voltage range from 6V to 42V
- Adjustable output voltage as low as 1.225V
- 1.5% feedback reference accuracy
- Operating frequency adjustable between 50kHz and 1MHz with a single resistor
- Master or slave frequency synchronization
- Adjustable soft-start
- Emulated Current Mode control architecture
- Wide bandwidth error amplifier
- Built-in protection: cycle-by-cycle current limit, short-circuit protection, thermal shutdown, and remote shutdown
- Power enhanced HTSSOP-20 package with an exposed die attach pad for thermal dissipation
Applications
The LM25576MHX-NS is well-suited for various applications requiring efficient step-down of high, unregulated input voltages. These include:
- Telecom power supplies
- Industrial power systems
- Automotive power bus voltage ranges
Q & A
- What is the input voltage range of the LM25576MHX-NS?
The input voltage range is from 6V to 42V.
- What is the maximum output current of the LM25576MHX-NS?
The maximum output current is 3A.
- What is the minimum output voltage that can be set for the LM25576MHX-NS?
The minimum output voltage is 1.225V.
- How is the operating frequency of the LM25576MHX-NS adjusted?
The operating frequency is adjusted using a single external resistor connected between the RT pin and the AGND pin.
- What type of protection features does the LM25576MHX-NS have?
The device features cycle-by-cycle current limit, short-circuit protection, thermal shutdown, and remote shutdown.
- What package type is the LM25576MHX-NS available in?
The device is available in a power enhanced HTSSOP-20 package with an exposed die attach pad.
- Can the LM25576MHX-NS be synchronized with other regulators or an external clock?
Yes, the LM25576MHX-NS has a frequency synchronization pin that allows it to self-synchronize or synchronize to an external clock.
- What is the thermal shutdown threshold of the LM25576MHX-NS?
The thermal shutdown threshold is 165 °C.
- Is the LM25576MHX-NS supported by any design tools?
Yes, it is supported by the full suite of WEBENCH® On-Line design tools.
- What is the purpose of the exposed pad in the HTSSOP-20 package?
The exposed pad aids in thermal dissipation by connecting to the ground plane of the PCB.
