Topology: Buck
Input Voltage (min.): 2.20 V
Input Voltage (max.): 5.50 V
Output 1: 3.90 V / 0.100 A

Original publication on 2017-06-09, revision .


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.


  • 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)• 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


  Order Code SPEC Product series L
RDC typ.
RDC max.
Montageart Samples
74438343022 PDF WE-MAPI SMT Power Inductor 2.2 1.1 2.5 225 270 70 SMT