ADP2503-EVALZ Analog Devices Inc, ADP2503-EVALZ Datasheet - Page 13

• Manufacturer Part Number: ADP2503-EVALZ
• Description: 600mA 2.5MHz Sync Step-up/Step-Down Reg
• Manufacturer: Analog Devices Inc

Specifications of ADP2503-EVALZ

• Main Purpose: DC/DC, Step Up or Down
• Current - Output: 600mA
• Voltage - Input: 2.5 ~ 5.5 V
• Regulator Topology: Buck-Boost
• Frequency - Switching: 2.5MHz
• Board Type: Fully Populated
• Utilized Ic / Part: ADP2503
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Power - Output: -
• Outputs And Type: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
INDUCTOR SELECTION
The high 2.5 MHz switching frequency of the ADP2503/
ADP2504 allows for minimal output voltage ripple, while
minimizing inductor size and cost. Careful inductor selection
also optimizes efficiency and reduces electromagnetic interfe-
rence (EMI). The selection of the inductor value determines
the inductor current ripple and loop dynamics.
where:
f
L is the inductor value in henries.
A larger inductor value reduces the current ripple (and, therefore,
the peak inductor current), but is physically larger in size with
increased dc resistance. Inductor values between 1 μH and
1.5 μH are suggested. The maximum inductor value to ensure
stability is 2.0 μH. For increased efficiency with the ADP2504,
it is suggested that a 1.5 μH inductor be used.
The inductor peak current is at the maximum in boost mode.
To determine the actual maximum inductor current in boost
mode, the input dc current should be estimated.
where η is efficiency (assume η ≈ 0.85 to 0.90).
The saturation current rating of the inductor must be at least
I
Ceramic multilayer inductors can be used with lower current
designs for a reduced overall solution size and dc resistance
(DCR). These are available in low profile packages. Care must
be taken because these derate quickly as the inductor value is
increased, especially at higher operating temperatures.
Ferrite core inductors have good core loss characteristics as well as
reasonable dc resistance. A shielded ferrite inductor reduces the
EMI generated by the inductor.
Table 6. Recommended Output Capacitors
Vendor
Murata
TDK
Murata
TDK
TDK
Murata
OSC
IN(MAX)
is the switching frequency (typically 2.5 MHz).


I
IN
I
I
+ ΔI
L
L
(
MAX
,
,
peak
peak
LOAD
)

/2.
(
(
I
Buck
Boost
LOAD
Value
2 × 10 μF, 6.3 V
2 × 10 μF, 6.3 V
22 μF, 6.3 V
22 μF, 6.3 V
22 μF, 10 V
2 × 10 μF, 10 V
)
(
)
MAX


V
(
)
OUT
V

V
OUT




V
IN
V

V
OUT
OUT

(

IN
V
V
f
IN
OSC
IN






)

V
η
1

OUT
L
f
OSC
V
)
IN

L
Part No.
GRM188R60J106ME47
C1608JB0J106K
GRM21BR60J226ME39
C2012X5R0J226M
C3216X5R1A226K
GRM21BR71A106KE51L
Rev. A | Page 13 of 16
Table 5. Sample of Recommended Inductors
Vendor
Toko
Toko
Toko
Murata
Murata
TDK
TDK
Coilcraft
Coilcraft
Taiyo
Yuden
Output Capacitor Selection
The output capacitor selection determines the output voltage
ripple, transient response, and the loop dynamics of the
ADP2503/ADP2504. The output voltage ripple for a given
output capacitor is as follows:
If the ADP2503/ADP2504 are operating in buck mode, the
worst-case voltage ripple occurs for the highest input voltage,
V
worst-case voltage ripple occurs for the lowest input voltage, V
The maximum voltage overshoot, or undershoot, is inversely
proportional to the value of the output capacitor. To ensure
stability and excellent transient response, it is recommended
to use a minimum of 22 μF X5R 6.3 V or 2 × 10 μF X5R 6.3 V
capacitors at the output. The effective capacitance (includes
temperature and dc bias effects) needed for stability is 14 μF.
IN
. If the ADP2503/ADP2504 are operating in boost mode, the


V
V
OUT
OUT
Value
(μH)
1.2
1.5
1
1
1.5
1.0
1.5
1.0
1.5
1.5
,
,
peak
peak
(
(
Boost
Buck
Part No.
DE2810C
DE2810C
MDT2520-CN
LQM2HP-G0
LQM2HP-G0
CPL2512T
CPL2512T
LPS3010
LPS3010
NR3015T1
)
)


Dimensions
L × W × H (mm)
1.6 × 0.8 × 0.8 (2)
1.6 × 0.8 × 0.8 (2)
2 × 1.25 × 1.25
2 × 1.25 × 1.25
2 × 1.25 × 1.25
2 × 1.25 × 1.25 (2)
V
I
C
LOAD
IN
OUT
V

OUT

8

ADP2503/ADP2504
(

V
DCR
(mΩ)
55
60
100
55
70
90
120
85
120
40
V

L
OUT
OUT
(

V

IN


f
OSC
V
f
I
(A)
1.7
1.5
1.8
1.6
1.5
1.5
1.2
1.7
1.3
1.5

SAT
OSC
IN
V

2
OUT
)

C
)
Dimensions
L × W × H
(mm)
2.8 × 2.8 × 1.0
2.8 × 2.8 × 1.0
2.5 × 2 × 1.2
2.5 × 2 × 1
2.5 × 2 × 1
2.5 × 1.5 × 1.2
2.5 × 1.5 × 1.2
3.0 × 3.0 × 0.9
3.0 × 3.0 × 0.9
3.0 × 3.0 × 1.5
OUT
IN
.