Power Monitoring Output, 5.5V Input, 200mA Synchronous Step-Down Switching Regulator with 260nA Quiescent Current S-85S1P Series

The S-85S1P 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-85S1P 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 function of the power monitoring output is prepared in the S-85S1P Series. The power monitoring output is a function that divides the input voltage (Vin) of the DC-DC converter into Vin/2 or Vin/3 and outputs the voltage. For example, this function makes it possible that the IC connects to a low voltage microcontroller A/D converter directly and the microcontroller monitors a battery voltage.


DC-DC converter block

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 limit function
450 mA (at L = 2.2 μH)
Automatic recovery type short-circuit protection function:Hiccup control
Input and output capacitors
Ceramic capacitor compatible

Power monitor block

Low current consumption
280 nA typ.
Input voltage
1.5 V to 5.5 V
Output voltage
Vin/2 (S-85S1PCxx)
Vin/3 (S-85S1PDxx)


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