as1339 austriamicrosystems, as1339 Datasheet - Page 20

• Manufacturer Part Number: as1339
• Description: 650ma Rf Step-down Dc-dc For Pa, With Two Ldos
• Manufacturer: austriamicrosystems

AS1339
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
f .... Switching Frequency (2.0MHz typical)
L .... Inductor Value
I
Δ
I
Accepting larger values of ripple current allows the use of low inductance values, but results in higher output voltage
ripple, greater core losses, and lower output current capability. The total losses of the coil have a strong impact on the
efficiency of the dc/dc conversion and consist of both the losses in the dc resistance and the following frequency-
dependent components:
Note: For highest efficiency, a low DC-resistance inductor is recommended.
Table 8. Recommended Inductors
www.austriamicrosystems.com
LMAX
OUTMAX
I
L
EPL2014-222MLC
EPL2014-332MLC
EPL2014-472MLC
XPL2010-222ML
XPL2010-332ML
MLP2520S1R5S
MLP2520S2R2S
MLP2520S3R3S
.... Peak to Peak inductor ripple current
1. The losses in the core material (magnetic hysteresis loss, especially at high switching frequencies)
2. Additional losses in the conductor from the skin effect (current displacement at high frequencies)
3. Magnetic field losses of the neighboring windings (proximity effect)
4. Radiation losses
Part Number
.... Maximum Inductor current
.... Applied load current
1.5µH
2.2µH
3.3µH
2.2µH
3.3µH
4.7µH
2.2µH
3.3µH
L
120m Ω
152m Ω
231m Ω
156m Ω
207m Ω
110m Ω
110m Ω
80m Ω
DCR
ΔI
I
L
LMAX
=
V
----------------------------------------------------- -
Revision 1.02
Current Rating Dimensions (L/W/T)
OUT
=
I
OUTMAX
V
0.925A
×
0.98A
0.65A
IN
1.5A
1.2A
1.0A
0.8A
1.2A
(
V
×
IN
f L
×
–
+
V
ΔI
--------
OUT
2
L
)
2.5x2.0x1.2mm
2.5x2.0x1.2mm
2.5x2.0x1.2mm
2.2x2.0x1.4mm
2.2x2.0x1.4mm
2.2x2.0x1.4mm
2.0x1.9x1.0mm
2.0x1.9x1.0mm
TDK
www.tdk.com
Coilcraft
www.coilcraft.com
Manufacturer
20 - 24
(EQ 3)
(EQ 4)