MAX1957EUB+ Maxim Integrated Products, MAX1957EUB+ Datasheet - Page 20

• Manufacturer Part Number: MAX1957EUB+
• Description: IC CNTRLR PWM BUCK 10-UMAX
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX1957EUB+

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.4 ~ 4.73 V
• Current - Output: 3A
• Frequency - Switching: 300kHz
• Voltage - Input: 3 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Power - Output: 444mW
• Duty Cycle (max): 89 %
• Output Voltage: 0.4 V to 4.73 V
• Output Current: 3000 mA
• Mounting Style: SMD/SMT
• Switching Frequency: 300 KHz
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Synchronous Pin: No
• Topology: Boost, Buck
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Low-Cost, High-Frequency, Current-Mode PWM
Buck Controller
Figure 6. Numerical Example to Calculate R
20
I
C
L
R
g
R
g
R
Pick the crossover frequency f
is not needed The power
G
R
C
V
A
f
f
f
then
And
OUT MAX
pMOD
S
zESR
OUT
ESR
mEA
DS ON
mc
LOAD
C
MOD f
OUT
VCS
C
______________________________________________________________________________________
1
(
1
:
(
MHz
:
H
g
I
( )
OUT MAX
mEA
I
A
OUT MAX
C
)
110
2 5
2
20
0 0025
V
6 3
VCS
2
V
.
)
.
OUT
.
I
OUT MAX
OUT
(
0 013
V
(
A
.
F
g
V
3
S
C
mc
.
OUT
A
V
(
1
C
OUT
R
V
FB
)
)
OUT
DS ON
OUT
1
)
R
(
(
(
f
f
S
LOAD
R
S
G
R
LOAD S
)
MOD f
ESR
2 5
L
3
L
.
R
)
mod
12 21
A
)
LOAD
R
V
( )
(
LOAD S
.
f
C
(
( )
f
1
ulator gain at f is
S
C
2
C
0 833
S
R
OUT
.
L
110
C
at at
f
)
L
20
f
)
S S
1 5
S
C
/
L
2 5
F
2 5
3
and C
1
f
.
L
pMOD
3
.
the switching frequency f
A
2 5
A
V
f
0 8
.
V
C
.
C
.
0025
V
C
V
R
(
(
1
ESR
1
Values of the Typical Operating Circuit of Figure 1 (MAX1953)
:
MHz
MHz
12 21
.
937
)
.
3 2
S
2
.
1
1
MHz
33
H
H
)
0 833
k
)
0 833
20
.
.
33
20
F
( ).
k k
S
F
(
(
1
0 833
We choose
1
0 833
MHz
.
MHz
.
270
pF
1
1
1
1
H
1
H
MHz
100
MHz
)
)
kHz
17 42
100
1
1
.
H
kHz
H
f
zESR
kHz
0 0025
,
.
so C
0
.
967
967
F
17 42
.
kHz