Power Electronics

High Ripple-Rejection Low Dropout High Output Current CMOS Voltage Regulator

Seiko's S-13A1 Series is a positive voltage regulator with a low dropout voltage, high output voltage accuracy, and low current consumption developed based on CMOS technology. A 2.2 µF small ceramic capacitor can be used, and the very small dropout voltage and the large output current due to the built-in transistor with low on-resistance are provided. The S-13A1 Series includes a load current protection circuit that prevents the output current from exceeding the current capacitance of the output transistor and a thermal shutdown circuit that prevents damage due to overheating. In addition to the types in which output voltage is set inside the IC, a type for which output voltage can be set via an external resistor is added to a lineup. Also, the S-13A1 Series includes an inrush current limit circuit to limit the excess inrush current at power-on and at turn-on the ON/OFF pin. High heat radiation HSOP-6 and small SOT-89-5, HSNT-6A packages realize high-density mounting.


  • Output voltage (internally set) : 1.0 V to 3.5 V, selectable in 0.05 V step, ±1.0% accuracy
  • Ceramic capacitor of 2.2 µF or more can be used for the input and output capacitors.
  • Input voltage : 1.5 V to 5.5 V
  • Dropout voltage : 70 mV typ. (products having the output of 3.0 V, IOUT = 300 mA)
  • Current consumption during operation : 60 µA typ., 90 µA max.
  • Current consumption during power-off : 0.1 µA typ., 1.0 µA max.
  • Built-in overcurrent protection circuit limits overcurrent of output transistor.
  • Built-in thermal shutdown circuit prevents damage caused by heat.
  • Built-in inrush current limit circuit limits excessive inrush current during start-up.
  • For types in which output voltage is internally set of HSOP-6, SOT-89-5,
  • Built-in ON / OFF circuit ensures long battery life.
  • Selectable discharge shunt circuit.
  • Packages : HSOP-6, SOT-89-5, HSNT-6A
  • Lead-free (Sn 100%), halogen-free
  • Operation temperature range: Ta = -40°C to +85°C
  • Pricing in quantities of 10,000: $0.55
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