AP2953AS8PRG

AP2953A is a monolithic synchronous rectified step-down regulator integrating MOSFETs with 100mΩ on-resistance, capable of delivering 3A load current over a wide input voltage range (4.75V - 18V). Current mode control provides excellent transient response and cycle-by-cycle current limiting. Adjustable soft-start time prevents inrush current at startup. In shutdown mode, input current is less than 1uA. The AP2953A is available in an SOP8-PP package, offering a compact system solution that minimizes external components. AP2953A is a synchronous rectified, current mode, step-down regulator. It regulates output voltage as low as 0.925V from input voltages ranging from 4.75V to 18V, supplying a maximum load current of 3A. AP2953A uses current control mode to regulate the output voltage. First, the output voltage is sensed at the FB pin via a resistor divider and amplified by an internal transconductance error amplifier. The output voltage is then controlled by comparing the COMP pin voltage with the internally sensed switch current. The converter uses a built-in N-channel MOSFET switch to step down the input voltage and regulate the output voltage. Since the high-side MOSFET gate voltage must exceed the input voltage, a bootstrap capacitor is connected between SW and BS to drive the high-side gate. When SW is low, the bootstrap capacitor is charged from the internal 5V supply. When the AP2953A FB pin exceeds 20% above the 0.925V regulation threshold, the overvoltage comparator trips, discharging the COMP pin and SS pin to ground and forcing the high-side switch to turn off.

Applications

• Discrete power systems
• Network systems
• FPGA, DSP, ASIC power supplies
• Green electronics
• Notebook computers

Key features

• 3A output current
• Input voltage range: 4.75V to 18V
• Integrated 100mΩ power MOSFET
• Adjustable output range: 0.925V to 15V
• Up to 95% efficiency
• Adjustable soft-start time
• Low-ESR ceramic capacitors for stable operation
• Fixed 370kHz switching frequency
• Cycle-by-cycle current limiting
• Undervoltage protection
• SOP8-PP package with enhanced thermal dissipation