µ PC1933
4. APPLICATION EXAMPLE
4.1 Application Example
Figure 4-1 shows an example circuit for obtaining +5 V/50 mA from a +3 V power supply.
Figure 4-1 Application Example
COM VIN = 3 V
C5
1 µF
RT 3.9 kΩ
C1
3300
pF
R1
30 kΩ
8765
FB RT GND OUT
µ PC1933
II DLY VCC VREF
1234
CDLY
0.1 µ F
C0
0.1 µ F
R2 47 kΩ
R5 150 Ω
R7
R3 20 kΩ
2.4 kΩ
VR4
1 kΩ
R6 470 Ω
Q1
C2
100
pF
Q2
R8
7.5 kΩ
L1 47 µ H
R9 68 Ω
C3 100 pF
R10
20 kΩ
D1
Q3
VO = + 5 V
IO = 50 mA
C4
68 µ F
COM
4.2 List of External Parts
The list below shows the external parts.
Table 4-1 List of External Parts
Symbol
C4
D1
L1
Q3
Q1
Q2
Parameter
Function
68 µ F Output capacitor
Schottkey diode
47 µ H Choke inductor
Switching transistor
Buffer transistor
Buffer transistor
Part number
20SA68M
D1FS4
636FY-470M
2SD2403
2SC1623
2SA812
Maker
SANYO
SHINDENGEN
TOKO
NEC
NEC
NEC
Remark
OS-CON, SA series
D73F series
Remarks 1. The capacitors that are not specified in the above list are multilayer ceramic capacitors.
2. The resistors that are not specified in the above list are 1/4W resistors.
16
Data Sheet G13690EJ3V0DS00