S-8533 Datasheet, PDF (10/31 Pages) Seiko Instruments Inc – STEP-DOWN, SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER

STEP-DOWN, SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER
S-8533 Series
Rev.2.3_00
Though the conditions mentioned above are required to prevent back-flow current, they are guidelines. Check the
validity by measuring the prototype or the actual device.
VIN CIN +
Back-flow current
L
V_OUT
VIN PDRV
NDRV
V SS
Coil
current I_L
+
Figure 9 Back-Flow Current
Coil current under no load
IL
109 mA
0 mA
I_OUT
−109 mA
ILmax.
ΔIL
Back-f low
current
ILmin.
Coil current when 109 mA
flows as a load
I_L
218 mA
ILmax.
109 mA
I_OUT
0 mA
ΔIL
ILmin.
Back-flow current = 0 mA
Figure 10 Example for No Back-Flow Current
10
Seiko Instruments Inc.