ABLIC S-8521F38MC-BPXT2U

The S-8520/8521 Series is a CMOS step-down switching regulator-controller with PWM control (S-8520 Series) and PWM / PFM switching control (S-8521 Series). The S-8520/8521 Series has a reference voltage source, an oscillation circuit, an error amplifier, and other components. The S-8520 Series provides low-ripple power, high efficiency, and excellent transient characteristics due to a PWM control circuit capable of varying the duty ratio linearly from 0% up to 100%. The S-8520/8521 Series also has a soft-start circuit that prevents overshoot at startup. The S-8521 Series works with either PWM control or PFM control. It normally operates using PWM control with a duty ratio of 25% to 100%, but under a light load, it automatically switches to PFM control with a duty ratio of 25%. The S-8520/8521 Series ensures high efficiency over a wide range of conditions for devices, from the standby mode to the operation. By adding external Pch power MOS FET or PNP transistor, coil, capacitor, and externally connected diode, the S-8520/8521 Series can function as a step-down switching regulator, and is ideal for power supply units of portable devices due to small SOT-23-5 and the feature of low current consumption. It is also ideal for AC adapters due to the input voltage up to 16 V.

• Low current consumption
  • During operation: 60 μA max. (A, B types), 21 μA max. (C, D types), 100 μA max. (E, F types)
  • During shutdown: 0.5 μA max.
• Input voltage:
  • 2.5 V to 16 V (B, D, F types)
  • 2.5 V to 10 V (A, C, E types)
• Output voltage: Selectable between 1.5 V and 6.0 V in 0.1 V step
• Duty ratio:
  • 0% to 100% PWM control (S-8520 Series)
  • 25% to 100% PWM / PFM switching control (S-8521 Series)
• External parts are Pch power MOS FET or PNP transistor, coil, diode, and capacitor only (When using PNP transistor, add base resistor and capacitor).
• Oscillation frequency:
  • 180 kHz typ. (A, B types)
  • 60 kHz typ. (C, D types)
  • 300 kHz typ. (E, F types)
• Soft-start function:
  • 8 ms. typ. (A, B types)
  • 12 ms. typ. (C, D types)
  • 4.5 ms. typ. (E, F types)
• With a shutdown function
• With a built-in overload protection circuit
  • Overload detection time:
    • 4 ms. typ. (A type)
    • 14 ms. typ. (C type)
    • 2.6 ms. typ. (E type)
• Lead-free, Sn 100%, halogen-free

• On-board power supplies of battery devices for mobile phone, electronic notebooks, PDAs.
• Power supplies for audio equipment, including portable CD players and headphone stereo equipment.
• Fixed voltage power supply for cameras, video and communication devices.
• Power supplies for microcomputers
• Conversion from NiH or four NiCd cells or two lithium-ion cells to 3.3 V / 3 V.
• Conversion of AC adapter input to 5 V / 3 V.