MAX1845
PRODUCTIONDual, High-Efficiency, Step-Down Controller with Accurate Current Limit
- Part Models
- 2
- 1ku List Price
- Starting From $2.37
Overview
- Ultra-High Efficiency
- Accurate Current-Limit Option
- Quick-PWM™ with 100ns Load-Step Response
- 1% VOUT Accuracy over Line and Load
- Dual Mode™ Fixed 1.8V/1.5V/Adj or 2.5V/Adj Outputs
- Adjustable 1V to 5.5V Output Range
- 2V to 28V Battery Input Range
- 200/300/420/540kHz Nominal Switching Frequency
- Adjustable Overvoltage Protection
- 1.7ms Digital Soft-Start
- Drives Large Synchronous-Rectifier FETs
- Power-Good Window Comparator
- 2V ±1% Reference Output
The MAX1845 is a dual PWM controller configured for step-down (buck) topologies that provides high efficiency, excellent transient response, and high DC output accuracy necessary for stepping down high-voltage batteries to generate low-voltage chipset and RAM power supplies in notebook computers. The CS_ inputs can be used with low-side sense resistors to provide accurate current limits or can be connected to LX_, using low-side MOSFETs as current-sense elements.
The on-demand PWM controllers are free running, constant on-time with input feed-forward. This configuration provides ultra-fast transient response, wide input-output differential range, low supply current, and tight load-regulation characteristics. The MAX1845 is simple and easy to compensate.
Single-stage buck conversion allows the MAX1845 to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the 5V system supply instead of the battery at a higher switching frequency) allows the minimum possible physical size.
The MAX1845 is intended for generating chipset, DRAM, CPU I/O, or other low-voltage supplies down to 1V. For a single-output version, refer to the MAX1844 data sheet. The MAX1845 is available in 28-pin QSOP and 36-pin thin QFN packages.
Applications
- 1.8V and 2.5V I/O Supplies
- Chipset/RAM Supplies as Low as 1V
- CPU Core Supplies
- Notebook Computers
Documentation
Data Sheet 1
Technical Articles 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| MAX1845ETX+ | LFCSP | ||
| MAX1845ETX+T | LFCSP |
This is the most up-to-date revision of the Data Sheet.
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