AME5296 Datasheet, PDF (9/14 Pages) Analog Microelectronics – Step Down DC/DC Converter

AME
AME5296
2A, 18V, 500KHz Synchronous
Step Down DC/DC Converter
When using tantalum or electrolytic capacitors, the ESR dominates the impedance at the switching frequency. For
simplification, the output ripple can be approximated to:
V_OUT
=
V_OUT
f ×L
×
1− ^VOUT
V_IN
× R _ESR
Setting the Output Voltage
The output voltage is using a resistive voltage divider connected from the output voltage to feedback pin. It divides the
output voltage down to the feedback voltage by the ratio:
V_FB
=
V_OUT
×
R₂
R₁ + R₂
The output voltage is:
V_OUT
=
0.8 ×
R₁ + R₂
R₂
n Typical Application Circuits
VIN
4.5V~18V
Ren1
18K
CIN2
NS
C_IN1
22uF
Ren2
10K
C3
1uF
C5
22nF
IN
BST
AME5296
EN
SW
R4
10Ω
C4
0.1uF
L1
4.7uH
VCC
SS
FB
GND
R1
40.2K
R3
33K
R2
12.7K
VOUT
3.3V/2A
C6
15pF
R5
0Ω
COUT 1
22uF
COUT2
22uF
V_OUT(V)
1.0
1.2
1.8
2.5
3.3
5.0
R1(KΩ)
20.5
30.1
40.2
40.2
40.2
40.2
R2(KΩ)
82.0
60.4
32.4
19.1
12.7
7.68
R3(KΩ)
82
82
56
33
33
33
L(µH)
1.5
1.5
2.2
3.3
4.7
6.8
C_IN(µF)
22
22
22
22
22
22
C_OUT(µF)
22x2
22x2
22x2
22x2
22x2
22x2
Rev. A.05
9