ADP2503 Analog Devices, ADP2503 Datasheet - Page 14

• Manufacturer Part Number: ADP2503
• Description: 600 mA, 2.5 MHz Buck-Boost DC-to-DC Converter
• Manufacturer: Analog Devices

ADP2503/ADP2504
Input Capacitor Selection
The ADP2503/ADP2504 require an input capacitor to filter
noise on the VIN pin, and provide the transient currents while
maintaining constant input and output voltage. A 10 μF X5R/
X7R ceramic capacitor rated for 6.3 V is the minimum recom-
mended input capacitor. Increased input capacitance reduces
the amplitude of the switching frequency ripple on the battery.
Because of the dc bias characteristics of ceramic capacitors, a
0603, 6.3 V, X5R/X7R, 10 μF ceramic capacitor is preferable.
Table 7. Recommended Input Capacitors
Vendor
Murata
TDK
OUTPUT VOLTAGE PROGRAMMING
The ADP2503/ADP2504 have an adjustable model where the
output is programmed through an external resistor divider.
The resistor divider is connected between VOUT and FB and
between FB and GND, and the combined total for the resistor
divider should be kept close to 400 kΩ. The typical voltage
reference (V
required, the following equation can be used to calculate the
value of the resistors:
V
OUT
Value
10 μF, 6.3 V
10 μF, 6.3 V
=
REF
⎛
⎜
⎜
⎝
R
) is 500 mV and depending on the output voltage
1
R
+
2
R
2
⎞
⎟
⎟
⎠
×
Part No.
GRM188R60J106ME47
C1608JB0J106K
V
REF
Dimensions
L × W × H
(mm)
1.6 × 0.8 × 0.8
1.6 × 0.8 × 0.8
Rev. B | Page 14 of 16
An example of the calculation for a required output voltage of
3.0 V follows.
Figure 30. Typical Application Circuit for the Adjustable ADP2503/ADP2504
2.3V TO 5.5V
3
0 .
V
V
IN
10µF
=
⎛
⎜
⎜
⎝
360
60
k
k
Ω
Ω
OFF
SYNC
ADP2503/ADP2504
⎞
⎟
⎟
⎠
SW1
PVIN
VIN
×
EN
ON
0
5 .
V
AGND
1.5µH
PGND
VOUT
SW2
FB
R1
R2
2.8V TO 5V
20µF
V
OUT