S-8520A20MC-AVFT2X Datasheet, PDF (17/44 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
1. 3 Overload protection circuit
Types are selectable the S-8520/8521 Series with the overload protection circuit (A, C and E types) or without
the overload protection circuit (B, D and F types).
By the S-8520/8521 Series with the overload protection circuit (A, C and E types), the switching components
and inductor can be protected because the overload protection circuit works and is set to the intermittent mode,
in case of overload or load short-circuit.
But in case of supplying current to load by using 100% duty cycle, select the S-8520/8521 Series without the
overload protection circuit (B, D and F types), according to the conditions of application.
The operation voltage differs in 10 V (A, B and E types) or 16 V (B, D and F types) whether the overload
protection circuit is available or not.
Table 9 shows items for selecting the type according to the requirements of application. Select it matching the
marks () for your requirement.
Table 9
Item
S-8520 Series
A BCDE F
The need of overload protection circuit



Input voltage exceeds 10 V
  
Focusing on efficiency of light load status
(1 mA or less)



Using with middle load current (about 200
mA)



Using with large load current (about 1 A)
 
Focusing on the low ripple voltage
 



Focusing on downsizing external parts


Remark : Indispensable condition
: Superiority of requirement
: Particularly superiority of requirement
S-8521 Series
A BCDE F



  
    

 
 

 






17