SC194BMLTRT Semtech, SC194BMLTRT Datasheet - Page 9

• Manufacturer Part Number: SC194BMLTRT
• Description: IC SYNC BUCK CONV 1A 10-MLP
• Manufacturer: Semtech
• Type: Step-Down (Buck)r

Specifications of SC194BMLTRT

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: Adjustable
• Current - Output: 1A
• Frequency - Switching: 1MHz
• Voltage - Input: 2.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MLP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: SC194BMLTR

Final inductor selection will depend on various design
considerations such as effi ciency, EMI, size and cost.
Table 1 lists the manufacturers of practical inductor
options.
C
The source input current to a buck converter is non-
continuous. To prevent large input voltage ripple a low
ESR ceramic capacitor is required. A minimum value of
10μF should be used for suffi cient input voltage fi ltering
and a 22μF should be used for improved input voltage
fi ltering.
C
The internal compensation is designed to work with a
certain output fi lter corner frequency defi ned by the
equation:
This single pole fi lter is designed to operate with a
minimum output capacitor value of 10μF. Larger output
capacitor values will improve transient performance.
If PSAVE operation is required the minimum capacitor
value is 22μF.
Output voltage ripple is a combination of the voltage
ripple from the inductor current charging and discharging
the output capacitor and the voltage created from the
inductor current ripple through the output capacitor ESR.
Selecting an output capacitor with a low ESR will reduce
the output voltage ripple component, as can be seen in
the following equation:
© 2006 Semtech Corp.
POWER MANAGEMENT
Applications Information (Cont.)
Manufacturer/Part No.
BI Technologies
HM66304R7
Coilcraft
D01608C-472ML
TDK
VLCF4018T- 4R7N1R0-2
IN
OUT
Selection
Selection
Table 1 — Recommended Inductors
V
V
Value
(μH)
4.7
4.7
4.7
OUT(ESR)
OUT(ESR)
f
f
C
C
2
2
0.072
0.101
DCR
0.09
(Ω)
L
L
1
1
I
I
L(ripple)
L(ripple)
Saturation
C
C
Current
OUT
OUT
1.32
1.07
(A)
1.5
ESR
ESR
Tolerance
COUT
COUT
(+%)
20
20
30
4.7 × 4.7 ×3.0
6.6 × 4.5 ×3.0
4.3 × 4.0 ×1.8
Dimensions
LxWxH
(mm)
9
Capacitors with X7R or X5R ceramic dielectric are
strongly recommended for their low ESR and superior
temperature and voltage characteristics. Y5V capacitors
should not be used as their temperature coeffi cients
make them unsuitable for this application. Table 2 lists
the manufacturers of recommended capacitor options.
Note: Where PSAVE operation is required 22μF must be used for C
Manufacturer/Part No.
Murata
GRM21BR60J226ME39L
Murata
GRM188R60J106MKE19
TDK
C2012X5R0J106K
Table 2 — Recommended Capacitors
Value
(μF)
22
10
10
Voltage
Rated
(VDC)
6.3
6.3
6.3
Characteristic
Temperature
X5R
X5R
X5R
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SC194B
Case Size
OUT
0805
0603
0603
.