Data Sheet ADP2164
Rev. 0 | Page 17 of 20
Table 6. Recommended L and C
OUT
Values at f
S
= 600 kHz
V
IN
(V) V
OUT
(V) L (μH) C
OUT
(μF)
3.3 1.0 1 100 + 100
3.3 1.2 1 100 + 100
3.3 1.5 1 100 + 47
3.3 1.8 1 100 + 47
3.3 2.5 1 100
5 1.0 1 100 + 100
5 1.2 1.5 100 + 100
5 1.5 1.5 100 + 47
5 1.8 1.5 100 + 47
5 2.5 1.5 100
5 3.3 1.5 100
Higher or lower values of inductors and output capacitors can
be used in the regulator, but system stability and load transient
performance must be verified.
Table 7 and Table 8 list some recommended inductors and
capacitors for the ADP2164.
Table 7. Recommended Inductors
Manufacturer Part No.
Coilcraft® MSS1038, MSS1048, MSS1260
Sumida CDRH103R, CDRH104R, CDRH105R
Table 8. Recommended Capacitors
Manufacturer Part No. Description
Murata GRM32ER60J107ME20 100 μF, 6.3 V, X5R, 1210
Murata GRM32ER60J476ME20 47 μF, 6.3 V, X5R, 1210
TDK C3225X5R0J107M 100 μF, 6.3 V, X5R, 1210
TDK C3225X5R0J476M 47 μF, 6.3 V, X5R, 1210
INPUT CAPACITOR SELECTION
The input capacitor reduces the input voltage ripple caused by
the switch current on PVIN. Place the input capacitor as close
as possible to the PVIN pins. A 22 μF or 47 μF ceramic capacitor
is recommended. The rms current rating of the input capacitor
should be larger than the value calculated using the following
equation:
()
DDII
ORMS
−××= 1
where
D is the duty cycle.
VOLTAGE TRACKING
The ADP2164 includes a tracking feature that allows the
ADP2164 output (slave voltage) to be configured to track
an external voltage (master voltage), as shown in Figure 39.
ADP2164
R
TOP
R
BOT
R
TRKT
R
TRKB
V
SLAVE
MASTER
TRK
FB
09944-039
Figure 39. Voltage Tracking
Coincident Tracking
A common requirement is coincident tracking, as shown in
Figure 40. Coincident tracking limits the slave output voltage
to the same value as the master voltage until the slave output
voltage reaches regulation. Connect the TRK pin to a resistor
divider driven from the master voltage, as shown in Figure 39.
For coincident tracking, set R
TRKT
= R
TOP
and R
TRKB
= R
BOT
.
OLTAGE
TIME
V
SLAVE
V
MASTER
09944-040
Figure 40. Coincident Tracking
Ratiometric Tracking
Ratiometric tracking is shown in Figure 41. The slave output is
limited to a fraction of the master voltage. In this application, the
slave and master voltages reach their final values at the same time.
OLTAGE
TIME
V
SLAVE
V
MASTER
09944-041
Figure 41. Ratiometric Tracking
The ratio of the slave output voltage to the master voltage is a
function of the two dividers.
TRKB
TRKT
BOT
TOP
MASTER
SLAVE
R
R
R
V
V
+
+
=
1
1
R
