5.5 V Input, 50 mA Synchronous Step-Down Switching Regulator with 260 nA Quiescent Current S-85S0A Series

The S-85S0A Series introduces own distinctive low power consumption control and COT (Constant On-Time) control, features ultra low current consumption (260 nA quiescent current) and fast transient response, operates at PFM control. The S-85S0A Series realizes high efficiency in a wide range of load current consumption and provides strong support for extended period operation of mobile devices and wearable devices which are equipped with compact batteries.
The S-85S0A Series can configure a step-down regulator only with a coil, an input capacitor, and an output capacitor. By using external parts recommended in this datasheet, the occupancy area can be reduced to 1.6 mm × 4.3 mm = 6.9 mm2, and it contributes to miniaturization of electronic equipment.


Ultra low current consumption
260 nA quiescent current
Efficiency (when under 100 μA load) : 90.5%
Fast transient response
COT control
Input voltage
2.2 V to 5.5 V
Output voltage
0.7 V to 2.5 V, in 0.05 V step
2.6 V to 3.9 V, in 0.1 V step
Output voltage accuracy
±1.5% (1.0 V ≤ VOUT ≤ 3.9 V)
±15 mV (0.7 V ≤ VOUT < 1.0 V)
High side power MOS FET on-resistance : 420 mΩ
Low side power MOS FET on-resistance : 320 mΩ
Soft-start function
1 ms typ.
Under voltage lockout function (UVLO)
1.8 V typ. (detection voltage)
Thermal shutdown function
135°C typ. (detection temperature)
Overcurrent limit function
300 mA (at L = 2.2 μH)
Automatic recovery type short-circuit protection function
Hiccup control
Input and output capacitors
Ceramic capacitor compatible
Operation temperature range
Ta = −40°C to +85°C
Lead-free (Sn 100%), halogen-free


  • Wearable device
  • Bluetooth device
  • Wireless sensor network device
  • Healthcare equipment
  • Smart meter
  • Portable game device