ER3105DI Datasheet, PDF (4/25 Pages) Altera Corporation – 500mA Wide VIN Synchronous Buck Regulator

Page 4
Typical Application Schematics
CBOOT
100nF
VOUT
COUT
10µF
L1
22µH
CVIN
10µF
1 _SS
2
SYNC
3 _BOOT
4 _PVIN
5 _SW
6
PGND
GND
FSW ¹²
11
COMP
10
FB
9
AVINO
POK
EN
R2
R3
CAVINO
1µF
CFB
FIGURE 3. INTERNAL DEFAULT PARAMETER SELECTION
CSS
CBOOT
100nF
VOUT
COUT
10µF
L1
22µH
CVIN
10µF
1 _SS
2
SYNC
3 _BOOT
4 _PVIN
5 _SW
6
PGND
GND
FSW ¹²
11
COMP
10
FB
9
AVINO
POK
EN
RFSW
R2
R3
CAVINO
1µF
RCOMP
CCOMP
CFB
V_OUT
(V)
12
5
3.3
2.5
1.8
L₁
(µH)
45
22
22
22
22
FIGURE 4. USER PROGRAMMABLE PARAMETER SELECTION
C_OUT
(µF)
10
2 x 22
2 x 22
2 x 22
22
TABLE 1. EXTERNAL COMPONENT SELECTION
R₂
(k)
R₃
(k)
C_FB
(pF)
R_FSW
(k)
90.9
4.75
22
115
90.9
12.4
100
120
90.9
20
100
120
90.9
28.7
100
120
100
50
22
120
R_COMP
(k)
100
100
100
100
50
C_COMP
(pF)
470
470
470
470
470
ER3105DI 500mA Wide VIN Synchronous Buck Regulator
09616
March 14, 2014
March 2014 Altera Corporation
Rev A