ADP2116-EVALZ AD [Analog Devices], ADP2116-EVALZ Datasheet - Page 23

• Manufacturer Part Number: ADP2116-EVALZ
• Description: Configurable, Dual 3 A/Single 6 A, Synchronous, Step-Down DC-to-DC Regulator
• Manufacturer: AD [Analog Devices]

CONVERTER CONFIGURATION
SELECTING THE OUTPUT VOLTAGE
To set the output voltage, V
fixed voltages, as shown in Table 4, by connecting the V1SET or
V2SET pin to GND through a resistor of an appropriate value
(see Figure 62). V1SET and V2SET set the voltage output levels
for Channel 1 and Channel 2, respectively. The feedback pin,
FB1 or FB2, should be directly connected to V
Table 4. Output Voltage Programming
R
0 Ω to GND
4.7 kΩ to GND
8.2 kΩ to GND
15 kΩ to GND
27 kΩ to GND
47 kΩ to GND
82 kΩ to GND
0 Ω to VDD
If the required output voltage, V
range, from 0.6 V to <1.6 V, connect V1SET or V2SET through
an 82 kΩ resistor to GND. For the adjustable output voltage range
of 1.6 V to 3.3 V, tie V1SET or V2SET to VDD (see Table 4). The
adjustable output voltage of the ADP2116 is externally set by a
resistive voltage divider from the output voltage to the feedback
pin (see Figure 63). The ratio of the resistive voltage divider sets
the output voltage, whereas the absolute value of these resistors
sets the divider string current. For lower divider string currents,
the small 10 nA (100 nA maximum) feedback bias current should
be taken into account when calculating the resistor values. The
feedback bias current can be ignored for a higher divider string
current; however, this degrades efficiency at very light loads.
V1SET
± 5%
V
0.8
1.2
1.5
1.8
2.5
3.3
0.6 to <1.6
(adjustable)
1.6 to 3.3
(adjustable)
OUT1
(V)
OUT1
OUT1
or V
R
0 Ω to GND
4.7 kΩ to GND
8.2 kΩ to GND
15 kΩ to GND
27 kΩ to GND
47 kΩ to GND
82 kΩ to GND
0 Ω to VDD
or V
V2SET
OUT2
OUT2
± 5%
, select one of the six
, is in the adjustable
OUT1
or V
V
0.8
1.2
1.5
1.8
2.5
3.3
0.6 to <1.6
(adjustable)
1.6 to 3.3
(adjustable)
OUT2
OUT2
(V)
.
Rev. 0 | Page 23 of 36
To limit output voltage accuracy degradation due to feedback
bias current to less than 0.05% (0.5% maximum), ensure that
the divider string current is greater than 20 μA. To calculate the
desired resistor values, first determine the value of the bottom
divider string resistor, R1, using the following equation:
where:
V
I
When R1 is determined, calculate the value of the top resistor, R2,
using the following equation:
STRING
REF
is the internal reference voltage, 0.6 V.
R1 = V
R2
is the resistor divider string current.
=
R1
REF
Figure 63. Configuration for Adjustable Outputs
⎡
⎢
⎣
/I
V
Figure 62. Configuration for Fixed Outputs
STRING
OUT
GND
ADP2116
GND
ADP2116
V
REF
−
R
V
FB1/FB2
R
FREQ
COMP1/
COMP2
V1SET/
PGNDx
FB1/FB2
FREQ
COMP1/
V2SET
REF
COMP2
V1SET/
PGNDx
V2SET
VINx
SWx
VINx
SWx
⎤
⎥
⎦
R
R
R
V1SET
R
V2SET
V1SET
V2SET
L
/
L
R2
R1
/
V
OUT1
V
OUT1
V
/V
V
IN
/V
IN
OUT2
OUT2
ADP2116
(2)
(3)