2.2MHz, Dual-Output Buck or Boost Converter with Internal Power MOSFETs

 

Part Number	Replacement	Explanation

Description

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The MAX5073 is a dual-output DC-DC converter with integrated high-side n-channel power MOSFETs. Each output can be configured either as a buck converter or a boost converter. The device is capable of operating from a wide 5.5V to 23V input voltage range. Each output is programmable down to 0.8V in the buck mode and up to 28V in the boost mode with an output voltage accuracy of ±1%. In the buck mode, converter 1 and converter 2 can deliver 2A and 1A, respectively. The output switching frequency of each converter can be programmed from 200kHz to 2.2MHz to avoid harmonics in a radio power supply or to reduce the size of the power supply. Each output operates 180° out-of-phase thus reducing input-capacitor ripple current, size, and cost. A SYNC input facilitates external frequency synchronization. Moreover, a CLKOUT output provides out-of-phase clock signal with respect to converter 2, allowing four-phase operation using two MAX5073 ICs in master-slave configuration.

The MAX5073 includes an internal digital soft-start that reduces inrush current, eliminates output-voltage overshoot, and ensures monotonic rise in output voltage during power-up. The device includes individual shutdown and a power-good output for each converter. Protection features include output short-circuit protection for buck mode and maximum duty-cycle limit for boost operation, as well as thermal shutdown.

The MAX5073 is available in a thermally enhanced 28-pin thin QFN package that can dissipate 2.7W at +70°C ambient temperature. The device is rated for operation over the -40°C to +85°C extended, or -40°C to +125°C automotive operating temperature range.

MAX5073: Functional Diagram Enlarge+

Key Features

• 4.5V to 5.5V or 5.5V to 23V Input Supply Voltage Range
• 0.8V (Buck) to 28V (Boost) Output Voltage
• Two Independent Output DC-DC Converters with Internal Power MOSFETs
• Each Output can be Configured in Buck or Boost Mode
• I_OUT1 and I_OUT2 of 2A and 1A (Respectively) in Buck Mode
• 180° Out-of-Phase Operation
• Clock Output for Four Phase Operation
• Switching Frequency Programmable from 200kHz to 2.2MHz
• Digital Soft-Start and Sync Input
• Individual Converter Shutdown and Power-Good Output
• Short-Circuit Protection (Buck)/Maximum Duty-Cycle Limit (Boost)
• Thermal Shutdown
• Thermally Enhanced 28-Pin Thin QFN Package Dissipates up to 2.7W at +70°C

Applications/Uses

• Networking Line Cards
• Point-of-Load DC-DC Converters
• Power-Over-Ethernet Postregulation for PDs
• Telecom Line Cards