19-3141; Rev 0; 1/04
KIT ATION EVALU E L B A AVAIL
Dual-Synchronous Buck Controllers for Point-ofLoad, Tracking, and D...
19-3141; Rev 0; 1/04
KIT ATION EVALU E L B A AVAIL
Dual-Synchronous Buck Controllers for Point-ofLoad, Tracking, and DDR Memory Power Supplies
General Description
The MAX8537/MAX8539 controllers provide a complete power-management solution for both double-data-rate (DDR) and combiner supplies. The MAX8537 and MAX8539 are configured for out-of-phase and in-phase DDR power-supply operations, respectively, and generate three outputs: the main memory
voltage (VDDQ), the tracking sinking/sourcing termination
voltage (VTT), and the termination reference
voltage (VTTR). The MAX8538 is configured as a dual out-of-phase controller for pointof-load supplies. Each buck controller can source or sink up to 25A of current, while the termination reference can supply up to 15mA output. The MAX8537/MAX8538/MAX8539 use constantfrequency
voltage-mode architecture with operating frequencies of 200kHz to 1.4MHz. An internal highbandwidth (25MHz) operational amplifier is used as an error amplifier to regulate the output
voltage. This allows fast transient response, reducing the number of output
capacitors. An all-N-FET design optimizes efficiency and cost. The MAX8537/MAX8538/MAX8539 have a 1% accurate reference. The second synchronous buck controller in the MAX8537/MAX8539 and the VTTR amplifier generate 1/2 VDDQ
voltage for VTT and VTTR, and track the VDDQ within ±1%. This family of controllers uses a high-side current-sense architecture for current limiting. ILIM pins allow the setting of an ...