The MAX5072 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 MAX5072 is designed to manage the power requirements of xDSL modems. The wide 5.5V to 23V input voltage range allows for the use of inexpensive AC adapters to power the device in xDSL modem applications. 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 the xDSL frequency band of operation. 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 MAX5072 ICs in master-slave configuration.
The MAX5072 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 a power-good output and power-on reset as well as manual reset. In addition, each converter output can be shut down individually. The MAX5072 features a "dying gasp" output, which goes low when the input voltage drops below a preprogrammed voltage. Protection features include output short-circuit protection for buck mode and maximum duty-cycle limit for boost operation, as well as thermal shutdown.
The MAX5072 is available in a thermally enhanced 32-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.
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