SC4525CSETRT Semtech, SC4525CSETRT Datasheet - Page 15
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SC4525CSETRT
Manufacturer Part Number
SC4525CSETRT
Description
IC BUCK ADJ 3A 8SOIC
Manufacturer
Semtech
Series
-r
Type
Step-Down (Buck), PWM - Current Moder
Datasheet
1.SC4525CSETRT.pdf
(21 pages)
Specifications of SC4525CSETRT
Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1 V ~ 26.88 V
Current - Output
3A
Frequency - Switching
300kHz ~ 1.3MHz
Voltage - Input
3 V ~ 28 V
Operating Temperature
-40°C ~ 105°C
Mounting Type
Surface Mount
Package / Case
8-SOIC (0.154", 3.90mm Width) Exposed Pad
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
SC4525CSETR
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
SC4525CSETRT
Manufacturer:
OHMITE
Quantity:
440 000
Company:
Part Number:
SC4525CSETRT
Manufacturer:
SEMTECH
Quantity:
2 832
Part Number:
SC4525CSETRT
Manufacturer:
SEMTECH/美国升特
Quantity:
20 000
P
P
BST
BST
F
F
R
R
SW
SW
DC
DC
+
+
Applications Information (Cont.)
In addition, the quiescent current loss is
The total power loss of the SC4525C is therefore
The temperature rise of the SC4525C is the product of the
total power dissipation (Equation (12)) and q
which is the thermal impedance from junction to ambient
for the SOIC-8 EDP package.
It is not recommended to operate the SC4525C above
125
P
P
Q
Q
o
C junction temperature.
P
P
P
P
P
P
P
P
P
P
P
P
P
P
Table 4. Typical switching time
C
C
BST
BST
D
D
IND
IND
Q
Q
TOTAL
TOTAL
SW
SW
=
=
=
=
=
=
Input Voltage
Input Voltage
=
=
=
=
D
D
=
=
1 (
1 (
V
V
=
=
1 (
1 (
IN
IN
1
1
2
2
D
D
⋅
⋅
12V
12V
24V
24V
28V
28V
−
−
V
V
P
P
1 .
1 .
⋅
⋅
⋅
⋅
⋅
⋅
CESAT
CESAT
) D
) D
C
C
2
2
t
t
V
V
S
S
mA
mA
BST
BST
~
~
+
+
⋅
⋅
⋅
⋅
1
1
P
P
V
V
V
V
⋅
⋅
⋅
⋅
D
D
3 .
3 .
SW
SW
IN
IN
I
I
40
40
O
O
I
I
⋅
⋅
I )
I )
O
O
⋅
⋅
I
I
+
+
⋅
⋅
O
O
I
I
O
O
2
2
O
O
12.5ns
12.5ns
25.3ns
25.3ns
P
P
22ns
22ns
⋅
⋅
BST
BST
⋅
⋅
1A
1A
F
F
R
R
SW
SW
DC
DC
+
+
Load Current
Load Current
P
P
Q
Q
15.3ns
15.3ns
25ns
25ns
28ns
28ns
2A
2A
P
P
Q
Q
=
=
V
V
IN
IN
18ns
18ns
28ns
28ns
31ns
31ns
3A
3A
⋅
⋅
JA
2
2
(11)
mA
mA
(12)
(36
o
C/W),
PCB Layout Considerations
In a step-down switching regulator, the input bypass
capacitor, the main power switch and the freewheeling
diode carry pulse current (Figure 9). For jitter-free
operation, the size of the loop formed by these components
should be minimized. Since the power switch is already
integrated within the SC4525C, connecting the anode of
the freewheeling diode close to the negative terminal of
the input bypass capacitor minimizes size of the switched
current loop. The input bypass capacitor should be placed
close to the IN pin. Shortening the traces of the SW and
BST nodes reduces the parasitic trace inductance at these
nodes. This not only reduces EMI but also decreases
switching voltage spikes at these nodes.
The exposed pad should be soldered to a large ground
plane as the ground copper acts as a heat sink for the
device. To ensure proper adhesion to the ground plane,
avoid using vias directly under the device.
V
IN
Figure 9. Heavy lines indicate the critical pulse
current loop. The stray inductance of this
loop should be minimized.
SC4525C
Z
L
V
OUT
15