LGS51215

LGS51215 is an adjustable-output DC-DC synchronous buck controller. It features a wide input voltage range of 4.5V to 24V. The output voltage can be dynamically switched via VID0 and VID1 logic signals, and the voltage transition slew rate is configurable through a capacitor connected from the VREF pin to ground. The feedback voltage FB is set via a resistor divider string between V1 and V2. The LGS51215 employs a current-sense control mode, reducing the complexity of the compensation network. It also delivers ultra-fast loop response with excellent output voltage overshoot suppression during dynamic load transitions. Inductor current sensing is used for current limiting, improving system conversion efficiency. A cycle-by-cycle current limiting function supporting up to 30A load current is provided, with the current limit value configurable via an external resistor as needed. Under light-load conditions, the LGS51215 adaptively transitions to PFM mode for improved light-load conversion efficiency. Additional features include: soft-start, thermal shutdown, UVLO, gate driver UVLO, and an intelligent current-limit shutdown timer. The LGS51215 is available in a compact 20-pin QFN 3×3 package.

Applications

• Laptop computers
• Desktop computers
• Industrial computers
• Bus-powered low-power CPU power rails

Key features

• Wide input voltage range: 4.5V to 24V
• Three selectable switching frequencies: 300K/400K/600KHz
• 2-Bit VID control with 4 configurable output voltage levels (including 0V)
• 0.65V internal reference voltage, ±1% output voltage accuracy
• Differential output voltage sensing: CSN-CSP
• Configurable output voltage slew rate
• Power Good (PG) indicator pin for normal output voltage
• Configurable Load Line compensation
• Fast transient response loop control
• Integrated dead-time control for power MOSFET gate drive
• Thermal shutdown, input undervoltage, output overvoltage/undervoltage protection
• Junction temperature range: -40°C to +125°C