Power Management ICs

5.5v Input, 200mA Synchronous Step-Down Switching Regulator with 260nA Quiescent Current S-85S1A Series

The S-85S1A Series introduces own distinctive low power consumption control and COT (Constant On-Time) control and features ultra low current consumption and fast transient response. PWM / PFM switching control automatically switches to PFM control when under light load, and the IC operates at ultra low current consumption of 260 nA quiescent current. The S-85S1A 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-85S1A 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 2.0 mm × 4.5 mm = 9.0 mm2, and it contributes to miniaturization of electronic equipment.


Ultra low current consumption
260 nA quiescent current
Efficiency (when under 100 μA load)
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)
Switching frequency
1.0 MHz (at PWM operation)
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 protection function
450 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

Parts List

  • These descriptions may be different from the actual product name and parameter.
    Please confirm the product name and specifications with the data sheet again.
  • The information herein is subject to change without notice.