LTC1530IS8#TRPBF Linear Technology, LTC1530IS8#TRPBF Datasheet - Page 13

• Manufacturer Part Number: LTC1530IS8#TRPBF
• Description: IC SW REG CNTRLR SYNC ADJ 8-SOIC
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LTC1530IS8#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 1.3 ~ 3.5 V
• Current - Output: 20A
• Frequency - Switching: 300kHz
• Voltage - Input: 3.3V, 5V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

APPLICATIO S I FOR ATIO
Table 1. Recommended MOSFETs for LTC1530 Applications
MANUFACTURER
Siliconix
Siliconix
ON Semiconductor
Fairchild
ON Semiconductor
IR
IR
Fuji
Note: Please refer to the manufacturer’s data sheet for testing conditions and detailed information.
*Users must consider the power dissipation and thermal effects in the LTC1530 if driving external MOSFETs with high values of input capacitance.
Refer to the PV
where L is the inductor value in H. With proper frequency
compensation, the combination of the inductor and output
capacitor values determine the transient recovery time. In
general, a smaller value inductor improves transient
response at the expense of ripple and inductor core
saturation rating. A 2 H inductor has a 0.9A/ s rise time
in this application, resulting in a 5.5 s delay in responding
to a 5A load current step. During this 5.5 s, the difference
between the inductor current and the output current is
made up by the output capacitor. This action causes a
temporary voltage droop at the output. To minimize this
effect, the inductor value should usually be in the 1 H to
5 H range for most 5V input LTC1530 circuits. Different
combinations of input and output voltages and expected
loads may require different values.
Once the required inductor value is selected, choose the
inductor core type based on peak current and efficiency
requirements. Peak current in the inductor is equal to the
maximum output load current plus half of the peak-to-
peak inductor ripple current. Inductor ripple current is set
by the inductor’s value, the input voltage, the output
voltage and the operating frequency. If the efficiency is
high, ripple current is approximately equal to:
CC
Supply Current vs GATE Capacitance in the Typical Performance Characteristics section.
MTB75N03HDL*
U
MTD20N03HDL
SUD50N03-10
PART NO.
Si4410DY
IRL3103S
FDS6680
2SK1388
IRLZ44
U
W
PACKAGE
TO-252
TO-220
TO-220
D
D
DPAK
SO-8
SO-8
2
2
PAK
PAK
U
RDS(ON)
AT 25 C
0.0075
0.019
0.020
0.035
0.014
0.028
0.037
0.01
( )
RATED CURRENT
where
f
L
Solving this equation for a typical 5V to 2.8V application
with a 2 H inductor, ripple current is:
Peak inductor current at 11.2A load:
The ripple current should generally fall between 10% and
40% of the output current. The inductor must be able to
withstand this peak current without saturating, and the
copper resistance in the winding should be kept as low as
possible to minimize resistive power loss. Note that in
OSC
O
11.5A at 25 C
10A at 100 C
16A at 100 C
59A at 100 C
40A at 100 C
36A at 100 C
15A at 25 C
10A at 25 C
20A at 25 C
75A at 25 C
56A at 25 C
50A at 25 C
35A at 25 C
8A at 75 C
I
11 2
= Inductor value
RIPPLE
300
= LTC1530 oscillator frequency
2 2
(A)
A
kHz
V
0 56
2
2
A
2
V
IN
f
H
OSC
12 2
TYPICAL INPUT
CAPACITANCE
V
Ciss (pF)
OUT
2
L
3200
2700
2070
4025
1600
3300
1750
A
880
A
O
P-P
V
V
IN
OUT
( C/W)
1.67
2.08
1.8
1.0
1.8
1.0
—
25
JC
LTC1530
T
( C)
175
150
150
150
150
175
175
150
JMAX
13
1530fa