Block Diagram
LA5754MP
VIN 1
Reg.
OCP
OSC
Reset
Comp.
Amp.
VREF
Drive
TSD
2 SWOUT
4 VOS
5 SS
3 GND
Application Circuit Example
VIN
SWOUT
L1
47µH
C1
1000µF
LA5754MP
SS
GND
C3
1µF
VOS
D1
SBD
R2
R1
C2
1000µF
Notes: C3 is for the soft start function. Delete C3 and keep the SS pin open when the soft function is not necessary.
Calculation equation to set the output voltage
This IC controls the switching output so that the VOS pin voltage becomes 2.66V (typ).
The equation to set the output voltage is as follows:
VO =
1+
R2
R1
× 2.66V(typ)
The VOS pin has the inrush current of 1µA (typ). Therefore, the error becomes larger when R1 and R2 resistance
values are large.
No.A0952-3/5