Quick-PWM SLAVE CONTROLLER FOR MULTIPHASE, STEP-DOWN SUPPLIES
SUNNYVALE, CA-February 19, 2002-Maxim Integrated Products introduces the MAX1980 step-down slave controller intended for low-voltage, high-current, multiphase DC-DC applications. The MAX1980 slave controller can be combined with any of Maxim’s DC-DC converters. Existing Quick-PWM™controllers, such as the MAX1718/MAX1907* function as the master controller, providing accurate output voltage regulation, fast transient response, and fault-protection features. Synchronized to the master’s low-side gate driver, the MAX1980 includes the Quick-PWM constant on-time controller with gate drivers for a synchronous rectifier, active-current balancing, and precision current-limit circuitry.
The MAX1980 provides the same high efficiency, ultra-low duty factor capability, and excellent transient response as other Quick-PWM controllers. The MAX1980 accurately balances the inductor currents and provides precise current-limit protection. The dual-purpose current-limit input also allows the slave controller to enter automatically a low-power standby mode when the master controller shuts down.
The MAX1980 features a driver disable mode that forces both gate drivers (DL and DH) low. While the MAX1980’s drivers are disabled, the master controller may operate in low-power skip mode, improving light-load efficiency. Additionally, the MAX1980 includes selectable trigger polarity, allowing the slave control to trigger on the rising (out-of phase) or falling (in-phase) edge of the master’s low-side gate driver. Out-of-phase operation staggers both the master’s and slave’s on-times, reducing the input ripple current and consequently the number of input capacitors. The MAX1980 also features a selectable 200kHz/300kHz/550kHz switching frequency.
The MAX1980 is available in a 20-pin QFN package. All devices are screened for the extended temperature range (-40°C to +85°C). Prices for the MAX1980 start at $2.24 (1000-up, FOB USA). A preassembled master/slave MAX1907/MAX1980 EVKIT (evaluation kit) is available with recommended external components to reduce design time.
*Future product? Contact factory for availability.
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