AS1324 AMSCO [austriamicrosystems AG], AS1324 Datasheet - Page 12

• Manufacturer Part Number: AS1324
• Description: 1.5MHz, 600mA, DC/DC Step-Down Regulator
• Manufacturer: AMSCO [austriamicrosystems AG]

AS1324
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
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:
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
Table 5. Recommended Inductors
Figure 26. Efficiency Comparison of Different Inductors, V
Output Capacitor Selection
The advanced fast-response voltage mode control scheme of the AS1324 allows the use of tiny ceramic capacitors.
Because of their lowest output voltage ripple low ESR ceramic capacitors are recommended. X7R or X5R dielectric
output capacitor are recommended.
At high load currents, the device operates in PWM mode and the RMS ripple current is calculated as:
While operating in PWM mode the overall output voltage ripple is the sum of the voltage spike caused by the output
capacitor ESR plus the voltage ripple caused by charging and discharging the output capacitor:
www.austriamicrosystems.com
CDRH3D16NP-2R2N
CDRH3D16ND-4R7N
MOS6020-222MLC
MOS6020-472MLC
LQH32CN2R2M33
LQH32CN4R7M33
LPS3008-222MLC
LPS3015-222MLC
Part Number
95
90
85
80
75
70
1
V
OUT
= 1.8V
Output Current (mA)
10
LQH32CN2R2
LPS3015-222
LQH32CN4R7
2.2µH
4.7µH
2.2µH
2.2µH
2.2µH
4.7µH
2.2µH
4.7µH
L
Δ V
OUT
100
I
RMSC
LPS3008-222
M OS6020-222
M OS6020-472
=
150m Ω
175m Ω
105m Ω
110m Ω
97m Ω
35m Ω
50m Ω
72m Ω
DCR
V
OUT
OUT
×
=
1
----------------------- -
1000
V
Revision 1.03
–
Current Rating Dimensions (L/W/T)
OUT
L
V
--------------
×
V
OUT
1100mA
2000mA
3260mA
1820mA
1200mA
790mA
650mA
900mA
IN
f
×
IN
1
----------------------- -
= 2.7V, V
×
–
L
⎛
⎝
V
--------------
------------------------------- -
8 C
×
V
95
90
85
80
75
70
OUT
×
IN
f
1
V
OUT
1
OUT
×
OUT
---------------- -
2
3.2x2.5x2.0mm
3.2x2.5x2.0mm
3.1x3.1x0.8mm
3.1x3.1x1.5mm
6.0x6.8x2.4mm
6.0x6.8x2.4mm
4.0x4.0x1.8mm
4.0x4.0x1.8mm
×
×
= 1.8V and 1.2V
= 1.2V
1
LQH32CN2R2
LPS3015-222
LQH32CN4R7
f
3
+
ESR
Output Current (mA)
10
⎞
⎠
LPS3008-222
M OS6020-222
M OS6020-472
Murata
www.murata.com
Coilcraft
www.coilcraft.com
Sumida
www.sumida.com
100
Manufacturer
1000
12 - 20
(EQ 4)
(EQ 5)