MAX1845 双路、高效率、降压型控制器，带有精确限流

快速浏览

技术文档

定购信息

更多信息

所有内容

概述

完整的数据资料 (PDF, 616kB)
英文

下载

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.

关键特性

应用/使用

Ultra-High Efficiency
Accurate Current-Limit Option
Quick-PWM™ with 100ns Load-Step Response
1% V_OUT 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

	1.8V与2.5V I/O电源
	芯片组/RAM供电，电压可低至1V
	CPU核电源
	笔记本电脑

Key Specifications: Switch-Mode DC-DC Power Supplies

Part Number

Topology

V_IN (min) (V)

V_IN (max) (V)

Number of DC-DC Outputs

Preset V_OUT (V)

Digital/VID Programmed Output

Min. Adjustable V_OUT (V)

Max. Adjustable V_OUT (V)

I_OUT (A)

Operating Current, I_CC (max) (mA)

Fixed Freq/PWM Operation

Operating Freq. (kHz)

Internal Power Switch(es)

Synchronous Rectifier

Industry Qualified

Package

Smallest Available Package (max w/pins) (mm²)

Price^**

MAX1845

Step-Down

1.5
1.8
2.5

5.5

1.5

Yes

540

Yes

Automotive - AECQ100
Automotive - General

QSOP/28
THIN QFN/36

$3.85 @ 1k

See All Switch-Mode DC-DC Power Supplies (418)

Notes:
^**This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.