2.2MHz Dual-Output Buck or Boost Converter for XDSL/ADSl2+ Modem Power Supplies
SUNNYVALE, CA-April 7, 2005-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX5072, a dual-output DC-DC converter with integrated high-side n-channel MOSFETs. The MAX5072 is designed to meet the low-cost, high-performance, and high-integration requirements of xDSL and ADSL2+ modem power supplies.
The device integrates four functions in one IC: two DC-DC converters with integrated high-side MOSFETs, a power-on-reset function with manual reset, and a "dying gasp" output which goes low when the input voltage drops below a preprogrammed voltage. The input voltage range is 4.5V to 5.5V or 5.5V to 23V for a loosely regulated, wall-adaptor power source. The two outputs are capable of delivering 1A and 2A, respectively, and each output can be configured as a buck or a boost converter. In some applications, one output may be configured as a boost converter to drive 12V line drivers. The switching
frequency is externally programmable from 200kHz to 2.2MHz. Designing the power supply to operate at 2.2MHz, for example, eliminates interference in the noise-sensitive ADSL2+ frequency band. As each converter runs 180º out-of-phase, the input ripple current and the size of the input capacitor are reduced. The MAX5072 uses external compensation, which allows use of the lowest cost inductors and output capacitors while optimizing loop stability and thereby reducing bill-of-material cost. By designing with the MAX5072, printed circuit-board area can be reduced by as much as 60% compared to competitive solutions that use multiple ICs.
The MAX5072 operates over the -40ºC to +85ºC extended temperature range and is available in a space-saving 5mm x 5mm, 32-pin TQFN package. Prices start at $1.90 (1000-up, FOB USA).
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