ADP1614-1.3-EVALZ Analog Devices, ADP1614-1.3-EVALZ Datasheet - Page 13

• Manufacturer Part Number: ADP1614-1.3-EVALZ
• Description: Power Management IC Development Tools Eval Board 1.3 MHz Switching Freq
• Manufacturer: Analog Devices
• Type: DC/DC Converters, Regulators & Controllersr
• Series: ADP1614r

Specifications of ADP1614-1.3-EVALZ

• Rohs: yes
• Tool Is For Evaluation Of: ADP1614
• Input Voltage: 2.5 V to 5.5 V
• Factory Pack Quantity: 1

Data Sheet
CHOOSING THE INPUT AND OUTPUT CAPACITORS
The
supply transient currents while maintaining constant input
and output voltages. Use low equivalent series resistance (ESR)
capacitors of 10 µF or greater to prevent noise at the
input. Place the capacitor between VIN and GND, as close as
possible to the ADP1614. Ceramic capacitors are preferable
because of their low ESR characteristics. Alternatively, use a
high value, medium ESR capacitor in parallel with a 0.1 µF low
ESR capacitor, placed as close as possible to the ADP1614.
The output capacitor maintains the output voltage and supplies
current to the load while the
and characteristics of the output capacitor greatly affect the
output voltage ripple and stability of the regulator. A low ESR
ceramic dielectric capacitor is preferable. The output voltage
ripple (∆V
where:
Q
C
I
t
The on time of the switch is determined as follows:
The input (V
switch duty cycle (D) as follows:
Choose the output capacitor based on the following equation:
Multilayer ceramic capacitors are recommended for this
application.
DIODE SELECTION
The output rectifier conducts the inductor current to the output
capacitor and load while the switch is off. For high efficiency,
minimize the forward voltage drop of the diode. For this reason,
using Schottky rectifiers is recommended. However, for high
voltage, high temperature applications, where the Schottky
rectifier reverse leakage current becomes significant and can
degrade efficiency, use an ultrafast junction diode.
Many diode manufacturers derate the current capability of the
diode as a function of the duty cycle. Verify that the output
ON
OUT
OUT
C
is the charge removed from the capacitor.
is the on time of the switch.
is the output load current.
ADP1614
is the output capacitance.
t
C
∆
D
ON
V
OUT
=
OUT
=
V
OUT
≥
OUT
f
=
D
V
SW
IN
I
) is calculated as follows:
f
OUT
C
) and output (V
OUT
SW
requires input and output bypass capacitors to
Q
−
OUT
V
C
×
×
IN
V
(
OUT
=
V
OUT
I
OUT
×
C
∆
−
OUT
V
×
V
ADP1614
OUT
IN
t
OUT
ON
)
) voltages determine the
switch is on. The value
ADP1614
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diode is rated to handle the average output load current with
the minimum duty cycle. The minimum duty cycle in CCM of
the
where V
The following are suggested Schottky diode manufacturers:
•
•
•
•
LOOP COMPENSATION
The
regulator loop, allowing optimization of the loop dynamics for a
given application.
The step-up converter produces an undesirable right-half plane
zero in the regulation feedback loop. This requires compensating
the regulator such that the crossover frequency occurs well below
the frequency of the right-half plane zero. The right-half plane
zero is determined by the following equation:
where:
F
R
divided by the load current.
To stabilize the regulator, ensure that the regulator crossover
frequency is less than or equal to one-fifth of the right-half
plane zero.
The regulator loop gain is
where:
A
V
V
V
G
R
Z
to GND.
G
current divided by the voltage at COMP), which is internally
set by the ADP1614.
Z
capacitor.
Z
LOAD
OUT
COMP
OUT
VL
FB
OUT
IN
MEA
CS
(RHP) is the right-half plane zero.
ADP1614
is the input voltage.
is the feedback regulation voltage, 1.245 V.
is the current sense transconductance gain (the inductor
is the loop gain.
ADP1614
ON Semiconductor
Diodes, Inc.
Toshiba
ROHM Semiconductor
= 67 MΩ.
is the impedance of the load in parallel with the output
D
F
is the regulated output voltage.
A
is the error amplifier transconductance gain.
is the equivalent load resistance or the output voltage
is the impedance of the series RC network from COMP
Z
VL
MIN
(
IN(MAX)
RHP
=
=
V
V
OUT
V
)
FB
is
is the maximum input voltage.
uses external components to compensate the
OUT
=




×
V
V
V
V
−
OUT
V
OUT
IN
OUT
V
IN
IN




(
×
MAX
2
×
G
2
MEA
)
R
π
LOAD
×
×
L
R
OUT
Z
COMP
×
G
ADP1614
CS
×
Z
OUT
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