1 Features

• Wide Input Voltage Range: 4.5 V to 42 V
• Internally Compensated Voltage Mode Control
• Stable with Low ESR Ceramic Capacitors
• 120 mΩ N-Channel MOSFET PFM Package
• 100 mΩ N-Channel MOSFET SO PowerPAD Package
• Output Voltage Options:
  -ADJ (Outputs as Low as 1.285 V)
  -5.0 (Output Fixed to 5 V)
• ±1.5% Feedback Reference Accuracy
• Switching Frequency of 500 kHz
• –40°C to 125°C Operating Junction
  Temperature Range
• Adjustable Soft-Start
• Adjustable Current Limit
• Integrated Boot-Strap Diode
• Fully Webench^® Enabled
• LM22673-Q1 is an Automotive Grade Product
  that is AEC-Q100 Grade 1 Qualified (–40°C to +125°C Junction Temperature)
• SO PowerPAD (Exposed Pad)
• PFM (Exposed Pad)

2 Applications

• Industrial Control
• Telecom and Datacom Systems
• Embedded Systems
• Conversions from Standard 24 V, 12 V and 5 V Input Rails

3 Description

The LM22673 switching regulator provides all of the functions necessary to implement an efficient high voltage step-down (buck) regulator using a minimum of external components. This easy to use regulator incorporates a 42 V N-channel MOSFET switch capable of providing up to 3 A of load current. Excellent line and load regulation along with high efficiency (> 90%) are featured. Voltage mode control offers short minimum on-time, allowing the widest ratio between input and output voltages. Internal loop compensation means that the user is free from the tedious task of calculating the loop compensation components. Fixed 5 V output and adjustable output voltage options are available. A switching frequency of 500 kHz allows for small external components and good transient response. An adjustable soft-start feature is provided through the selection of a single external capacitor. In addition, the switch current limit can be programmed with a single external resistor, allowing solution optimization. The LM22673 device also has built-in thermal shutdown, and current limiting to protect against accidental overloads.

The LM22673 device is a member of Texas Instruments' SIMPLE SWITCHER® family. The SIMPLE SWITCHER^® concept provides for an easy to use complete design using a minimum number of external components and the TI WEBENCH® design tool. TI's WEBENCH^® tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Application Schematic