MP2104 MPS, MP2104 Datasheet - Page 9

• Manufacturer Part Number: MP2104
• Description: 1.7mhz, 600ma Synchronous Step-down Converter
• Manufacturer: MPS

APPLICATION INFORMATION
Output Voltage Setting (MP2104DJ)
The external resistor divider sets the output
voltage (see Figure 3). The feedback resistor R1
also sets the feedback loop bandwidth with the
internal compensation capacitor (see Figure 1).
Choose R1 around 300kΩ for optimal transient
response. R2 is then given by:
MP2104 Rev. 1.4
5/28/2008
Manufacturer
Manufacturer
Table 1—Resistor Selection vs. Output
Taiyo Yuden
V
1.2V
1.5V
1.8V
2.5V
Coilcraft
Coilcraft
Sumida
Sumida
Sumida
Sumida
Murata
OUT
Toko
Table 3—Inductors for Improved Efficiency at 25mA, 50mA, under 100mA Load.
Voltage Setting
300k
300k
300k
300k
R
DO1605T-103MX
LQH4C100K04
Part Number
Part Number
CMD4D06-100
2
LP1704-222M
CDRH3D16
=
R1
CR32-100
CR54-100
Ω
Ω
Ω
Ω
LBC2518
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
D312C
V
0
(1%)
(1%)
(1%)
(1%)
6 .
OUT
R
V
1
Table 2—Suggested Surface Mount Inductors
−
MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER
1
95.3k
300k
200k
150k
Inductance (µH)
Inductance (µH)
R2
Ω
Ω
Ω
Ω
© 2008 MPS. All Rights Reserved.
(1%)
(1%)
(1%)
(1%)
2.2
2.2
2.2
2.2
10
10
10
10
10
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Max DCR (Ω)
Max DCR (Ω)
Inductor Selection
A 1µH to 10µH inductor with DC current rating
at least 25% higher than the maximum load
current is recommended for most applications.
For best efficiency, the inductor DC resistance
shall
recommended inductors and manufacturers.
For most designs, the inductance value can be
derived from the following equation:
Where ∆I
inductor ripple current approximately 30% of the
maximum load current, 600mA.
The maximum inductor peak current is:
Under light load conditions below 100mA, larger
inductance is recommended for improved
efficiency. Table 3 lists inductors recommended
for this purpose.
0.072
0.07
0.14
0.13
0.3
0.2
0.3
0.2
0.1
be
L
is the inductor ripple current. Choose
<200mΩ.
L
I
Current (A)
Current (A)
=
( L
Saturation
Saturation
MAX
V
OUT
V
1.7
1.0
1.2
0.6
1.0
1.2
0.7
1.0
1.2
)
IN
=
×
×
I
LOAD
(
∆
V
I
IN
See
L
×
−
+
f
OSC
V
∆
OUT
2
I
L
LxWxH (mm
Table
Dimensions
)
2.5x1.8x1.8
6.5x5.3x2
3.6x3.6x1
I
4x4x1.8
RMS
0.9
0.8
0.5
0.7
1.4
(A)
2
3
)
for
9