S-8327 Seiko, S-8327 Datasheet - Page 14

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

External parts selection for DC-DC converter
The relationship between majorcharacteristics of the step-up circuit and characteristics parameters of the external parts are
shown in Figure 6.
for large output current?
small inductance
external switching transistor
(small ON resistance)
Figure 6 Relationship between major character stics of the step-up circuit and external parts
small resistance of external resistor
Rb when an external switching
transistor is used
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
small DC resistance of inductor
operation efficiency
Seiko Instruments Inc.
for high efficiency?
stand-by efficiency
external resistor Rb when
built-in switching
an external switching
large resistance of
transistor is used.
transistor
large inductance
large output capacitance
for small ripple voltage
S-8323/8327 Series
13