S-8327 Seiko, S-8327 Datasheet - Page 52

• Manufacturer Part Number: S-8327
• Description: (S-8323 / S-8327) SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
• Manufacturer: Seiko

Collection of Product FAQs
Author: Tachibana Midori
<Information level>
<Product>
Related Documents:
Question:
Answer:
<Remarks>
B:
Index:
Division name: 01 IC
Category 1:
Category 2:
Cal No.:
How can the duty ratio in the boosting motion of a 100-kHz product be calculated?
Basically, the duty ratio at the time of the boosting motion varies depending on such conditions as the
input voltage VIN, output voltage VOUT, load current IOUT, coil value L, oscillation frequency fosc, and
Schottky diode voltage VF. If these conditions are known, the duty ratio can be roughly computed using
the following equation:
(The above equation can be derived from Formulas (4) and (17) in the Data Book and Duty = ton x
fosc.)
However, it is essential that the duty value given by the above equation be smaller than the duty value
computed below (non-continuous mode).
Duty
FAQ No.: 11S8323010
Duty
=
L
duty
×
fosc
=
(VOUT
÷
For Distri & Rep (Printing N.G.)
B: Technical
11 Power Supply
4. Switching Regulators
S-8323/24/27/28
VIN
×
-
VF
(2
-
×
VIN)
IOUT
Date: 98/11/12 (Thursday) 10:17 (Modified:)
÷
(VIN
×
(VOUT
+
(VOUT
-
VF
51
-
-
VF
VIN)
-
VIN))
÷
fosc
÷
L)