S-8363 Series Super Small Package Step-Up PWM/PFM Regulator Released
NEU ISENBURG, Germany, August 12, 2010-- Seiko Instruments officially released a new Step-Up DC-DC converter IC
Series S-8363 that is unique in a number of ways. It is available in SOT-23-6
and tiny SNT-6A package which measures mere 1.6mm x 1.8mm x 0.5mm, enabling
tight designs of small portable equipment. It incorporates a N-ch power MOS
FET with ON resistance of only 0.25 Ohm, permitting output current of 300mA
(@ VIN = 1.8V, VOUT = 3.3V). The input voltage range from 0.9V to 4.5V makes
it suitable for use with single or double cell dry batteries or with Li-Ion
batteries. The output voltage can be set between 1.8V and 5.0V. The switching
frequency is 1.2 MHz and the change over from PFM to PWM is set to 13%
typical. Operation is in PWM under heavy load with duty cycles up to 88%
(plus or minus6%) and in PFM under moderate to small load. The switching
regulator employs a soft start function over typical 1.2ms. An intelligent
STU-Mode Circuit supports the step-up of the output voltage for a given
Start-Up period with a fixed duty cycle; it is shut down during operation for
power saving. Current consumption is very dependent on the operating modus
and load; it is typ. 95 microA during switching stop and 3.0 microA with
power off pin set to OFF. Efficiency is 85%. The control circuit permits the
use of low ESR ceramic capacitors at the output. The IC contains an
over-current detection circuit to protect coil and switching regulator.