S-8520A20MC-AVFT2X Datasheet, PDF (3/44 Pages) Seiko Instruments Inc – SWITCHING REGULATOR CONTROLLER

STEP-DOWN, PWM CONTROL or PWM / PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
Rev.9.0_01
S-8520/8521 Series
 Block Diagrams
1. S-8520 Series
Tr
VIN
EXT
V_IN
+
SD
C_IN
L
Oscillation
circuit
Reference voltage
source with soft-start _VOUT
PWM control
+
circuit
−
+
C_OUT
V ______
ON/OFF
VSS
______
ON/OFF
Remark All the diodes in the figure are parasitic diodes.
Figure 1
2. S-8521 Series
Tr
VIN
EXT
V_IN
+
C_IN
SD
L
Oscillation
circuit
Reference voltage
source with soft-start _VOUT
PWM / PFM switching
+
control circuit
−
+
C_OUT
V ______
ON/OFF
VSS
______
ON/OFF
Remark All the diodes in the figure are parasitic diodes.
Figure 2
3