S-8363B-I6T1U2 Datasheet, PDF (10/50 Pages) Seiko Instruments Inc – PWM/PFM SWITCHABLE SWITCHING REGULATOR

STEP-UP, SUPER-SMALL PACKAGE, 1.2 MHz PWM/PFM SWITCHABLE SWITCHING REGULATOR
S-8363 Series
Rev.2.0_01
2. 3 Schottky barrier diode
A schottky barrier diode (SD) is necessary to operate the S-8363 Series. The VOUT pin also works as the
power supply pin. The voltage applied on the VOUT pin when ON / OFF = “L” is VIN − VD. VD is forward voltage
for step-down of SD, and largely varies depending on the forward current If of SD and ambient temperature, but
Vd is approx. 0.2 V to 0.5 V.
When the S-8363 Series startups from 0.9 V, use a SD with specially low VD. When using CRS08 for the
S-8363 Series, start-up is guaranteed when Ta = +25°C and a load current of 1 mA.
Satisfy the following conditions when using other SDs.
• Low forward voltage (VD)
• High switching speed
• Reverse withstand voltage of VOUT + spike voltage or more
• Rated current of IPK or more
Table 7 Typical Schottky Diodes
Manufacturer
TOSHIBA CORPORATION
ROHM Co., Ltd.
Name
CRS02
CRS08
RB161M-20TR
RB051LA-40TR
RB070M-30TR
RB161SS-20T2R
Remark
Generally, in diodes with low forward volage VD, reverse leakage current Ir tends to increases.
Especially, increase of Ir in high temperature is significant. To prevent decrease in efficiency, choose a
diode with low Ir when low voltage start-up is unnecessary.
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