MAX15035ETL+ Maxim Integrated Products, MAX15035ETL+ Datasheet - Page 21

• Manufacturer Part Number: MAX15035ETL+
• Description: IC REG STEP DOWN 15A 40-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX15035ETL+

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 1.05V, 1.5V
• Current - Output: 15A
• Voltage - Input: 4.5 ~ 26 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 40-TQFN Exposed Pad
• Power - Output: 2.16W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The output filter capacitor must have low enough equiv-
alent series resistance (ESR) to meet output ripple and
load-transient requirements. Additionally, the ESR
impacts stability requirements. Capacitors with a high
ESR value (polymers/tantalums) do not need additional
external compensation components.
In core and chipset converters and other applications
where the output is subject to large-load transients, the
output capacitor’s size typically depends on how much
ESR is needed to prevent the output from dipping too
low under a load transient. Ignoring the sag due to
finite capacitance:
Figure 8. Standard Application with Foldback Current-Limit Protection
15A Step-Down Regulator with Internal Switches
LO
AGND
(
GND/OPEN/REF/V
R
HI
ESR
5V BIAS
SUPPLY
______________________________________________________________________________________
ON
+
97.6kΩ
Output Capacitor Selection
R
R3
AGND
AGND
PCB
AGND
OFF
CC
)
≤
Δ
1000pF
54.9kΩ
I
1μF
LOAD MAX
C2
C3
49.9kΩ
100kΩ
R2
V
1μF
R10
C1
STEP
R1
PWR
(
37
38
36
34
35
4
2
)
3, 28, EP1
PGOOD
EN
REF
REFIN
V
V
SKIP
PWR
DD
CC
MAX15035
AGND
AGND
PGND
TON
ILIM
BST
LX
FB
IN
29
33
18–26, EP3
6–15
32
30
5, 16, EP2
In low-power applications, the output capacitor’s size
often depends on how much ESR is needed to maintain
an acceptable level of output ripple voltage. The output
ripple voltage of a step-down controller equals the total
inductor ripple current multiplied by the output capaci-
tor’s ESR. The maximum ESR to meet ripple require-
ments is:
where f
200kΩ
PWR
R
TON
R8
100kΩ
R5
49.4kΩ
AGND
49.9kΩ
SW
R4
R
C
0.1μF
is the switching frequency.
BST
ESR
REF
≤
L1
⎡
⎢
⎢
⎣
(
V
IN
V
IN
−
V
SEE TABLE 1 FOR COMPONENT SELECTION.
×
OUT
f
SW
)
×
PWR
C
C
V
PWR
OUT
IN
L
OUT
⎤
⎥
⎥
⎦
7V TO 24V
V
1.50V 10A
INPUT
1.05V 7A
OUTPUT
RIPPLE
21