S-85S1A Series

www.sii-ic.com

5.5 V INPUT, 200 mA SYNCHRONOUS STEP-DOWN

SWITCHING REGULATOR WITH 260 nA QUIESCENT CURRENT

© SII Semiconductor Corporation, 2017

1

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 mm

and it contributes to miniaturization of electronic equipment.



Features



Applications

• Ultra low current consumption:

260 nA quiescent current

• Wearable device

• Efficiency (when under 100 μA load):

90.5%

• Bluetooth device

• Fast transient response:

COT control

• Wireless sensor network device

• Input voltage:

2.2 V to 5.5 V

• Healthcare equipment

• Output voltage:

0.7 V to 2.5 V, in 0.05 V step

• Smart meter

2.6 V to 3.9 V, in 0.1 V step

• Portable game device

• Output voltage accuracy:

±1.5% (1.0 V



Package

• SNT-6A

(1.80 mm

× 1.57 mm × t0.5 mm max.)

±15 mV (0.7 V

• Switching frequency:

1.0 MHz (at PWM operation)

• High side power MOS FET on-resistance:

420 m

Ω

• Low side power MOS FET on-resistance:

320 m

Ω

• 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

• Operation temperature range:

Ta =

−40°C to +85°C

• Lead-free (Sn 100%), halogen-free



Typical Application Circuit

VSS

VIN

10

F

PVSS

VOUT

EN

SW

10

F

L

2.2

H



Efficiency

0.1

1

10

0.01

1000

100

0

100

80

60

40

20