FASTEST TRANSIENT RESPONSE, ±25A, STEP-DOWN DC-DC CONTROLLERS OPERATE DOWN TO 0.6VOUT
SUNNYVALE, CA-December 2, 2003-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX8553/MAX8554 DC-DC step-down controllers that offer high reliability and ensure balanced current sourcing and sinking capability of ±25A. They provide point-of-load supplies in servers, storage and networking systems, VGA cards, and modules. The MAX8553, which is pin compatible with the MAX1917, generates 1/2VREFIN voltage for VTT and VTTR voltages in DDR and RDRAM memory applications. The VTT and VTTR tracking voltages are maintained within 1% of 1/2VREFIN. The MAX8554 is a nontracking step-down controller with a 4.5V to 28V input voltage and a low 0.6V-feedback threshold voltage.
Using Maxim's proprietary ultra-high-bandwidth Quick-PWM™ architecture, the MAX8553/MAX8554 provide the fastest response to load-step transients and dramatically reduce required output capacitance. For example, a +8A to -8A step settles in less than 40µs with two 470µF output capacitors. Output regulation is 72mV on a 1.25V output. With no additional bias-supply requirement, a single 4.5V to 28V input provides flexibility for designers. Powerful gate drivers rated at 1.4 allow a wide range of output currents from 1A to 25A. Operating with 90% efficiency and a 5µA low shutdown current, these devices reduce heat in dense servers and extend battery life in notebook computers.
Output current monitoring is achieved without current-sense resistors, and the current-limit threshold is programmable through an external resistor. Adjustable foldback current limit helps withstand a continuous-output overload or a catastrophic short circuit while providing immunity to spurious current transients. Overvoltage protection shuts the converter down, and immediately discharges the output capacitor and clamps the output to ground.
The MAX8553/MAX8554 are available in space-saving 16-pin QSOP packages specified for the extended-industrial temperature range (-40°C to +85°C). Prices for the MAX8553EEE/MAX8554EEE start at $1.69 (1000-up, FOB USA). An evaluation kit and several production-ready circuits are available to speed designs.
Quick-PWM is a trademark of Maxim Integrated Products.
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