The MAX1937/MAX1938/MAX1939 comprise a family of synchronous, two-phase, step-down controllers capable of delivering load currents up to 60A. The controllers utilize Quick-PWM control architecture in conjunction with active load-current voltage positioning. Quick-PWM control provides instantaneous load-step response, while programmable voltage positioning allows the converter to utilize full transient regulation limits, reducing the output capacitance requirement. The two phases operate 180° out-of-phase with an effective 500kHz switching frequency, thus reducing input and output current ripple, as well as reducing input filter capacitor requirements. The MAX1937/MAX1938/MAX1939 are compliant with AMD Hammer, Intel Voltage-Regulator Module (VRM) 9.0/9.1, and AMD Athlon Mobile VID code specifications (see Table 1 for VID codes). The internal DAC provides ultra-high accuracy of ±0.75%. A controlled VID voltage transition is implemented to minimize both undervoltage and overvoltage overshoot during VID input change. Remote sensing is available for high output-voltage accuracy. The MOSFET switches are driven by a 6V gate-drive circuit to minimize switching and crossover conduction losses to achieve efficiency as high as 90%. The MAX1937/MAX1938/MAX1939 feature cycle-by-cycle current limit to ensure that the current limit is not exceeded. Crowbar protection is available to protect against output overvoltage.
Feature
- ±0.75% Output Voltage Accuracy
- Instant Load-Transient Response
- Up to 90% Efficiency Eliminates Heatsinks
- Up to 60A Output Current
- 8V to 24V Input Range
- User-Programmable Voltage Positioning
- Controlled VID Voltage Transition
- 500kHz Effective Switching Frequency
- MAX1937: AMD Hammer Compatible
- MAX1938: Intel VRM 9.0/9.1 Compatible
- MAX1939: AMD Athlon Mobile Compatible
- Soft-Start
- Power-Good (PWRGD) Output
- Cycle-by-Cycle Current Limit
- Output Overvoltage Protection (OVP)
- RDS(ON) or RSENSE Current Sensing
- Remote Voltage Sensing
- 28-Pin QSOP Package
Applications
- Blade Servers
- High-End Switches and Routers
- High-End Switches and Routers
- Macro Base Stations
- Notebook and Desktop Computers
- Servers and Workstations