ADP2386-EVALZ Analog Devices, ADP2386-EVALZ Datasheet - Page 17

• Manufacturer Part Number: ADP2386-EVALZ
• Description: Power Management IC Development Tools 20V 6A Evaluation Board
• Manufacturer: Analog Devices
• Type: DC/DC Converters, Regulators & Controllersr
• Series: ADP2386r

Specifications of ADP2386-EVALZ

• Rohs: yes
• Tool Is For Evaluation Of: ADP2386
• Input Voltage: 4.5 V to 20 V
• Factory Pack Quantity: 1

Data Sheet
The selected output capacitor voltage rating must be greater
than the output voltage. The rms current rating of the output
capacitor must be larger than the value that is calculated by
using the following equation:
PROGRAMMING THE INPUT VOLTAGE UVLO
The
program the UVLO threshold of the input voltage (see Figure 31).
Use the following equations to calculate R
where:
V
V
COMPENSATION DESIGN
For peak current-mode control, the power stage can be simplified
as a voltage controlled current source supplying current to the
output capacitor and load resistor. It is composed of one domain
pole and a zero that is contributed by the output capacitor ESR.
The control-to-output transfer function is based on the following:
where:
A
R is the load resistance.
C
R
ESR
IN_RISING
IN_FALLING
VI
OUT
= 8.7 A/V.
is the equivalent series resistance of the output capacitor.
ADP2386
I
R
R
G
f
f
is the output capacitance.
Z
P
C OUT _RMS
TOP_EN
BOT_EN
VD
=
=
is the V
(s) =
2
2
is the V
×
×
Figure 31. Programming the Input Voltage UVLO
R
R
=
=
TOP_EN
π
π
BOT_EN
=
. 1
V
V
has a precision enable input that can be used to
×
×
V
IN
I ∆
07
IN
COMP
OUT
(
R
12
IN
_
R
1
L
rising threshold.
ESR
V
RISING
falling threshold.
. 1
+
(
PVIN
×
1
(
s
07
×
R
EN
s
V
)
ESR
)
C
. 1
IN
−
V
OUT
= A
17
_
)
R
RISING
×
×
1µA
TOP
V
5
VI
C
μA
×
_
OUT
× R ×
EN
R
−
TOP
4µA
−
1.17V
. 1
×
. 1
ADP2386
17
5
_
17
EN CMP

 


 

EN
μA
1
1
V
V
TOP_EN
+
+
−
×
×
2
2
V
. 1
1
×
×
IN
17
μA
π
π
and R
_
s
s
FALLING
V
×
×
f
f
Z
P
BOT_EN

 


 

:
Rev. A | Page 17 of 24
The
amplifier and to compensate the system. Figure 32 shows the
simplified, peak current-mode control, small signal circuit.
The compensation components, R
and R
The closed-loop transfer equation is as follows:
The following design guideline shows how to select the R
and C
capacitor applications:
1.
2.
3.
4.
ADIsimPOWER DESIGN TOOL
The
set. ADIsimPower is a collection of tools that produce complete
power designs that are optimized for a specific design goal. The
tools enable the user to generate a full schematic and bill of
materials and calculate performance in minutes. ADIsimPower
can optimize designs for cost, area, efficiency, and part count,
while taking into consideration the operating conditions and
limitations of the IC and all real external components. For more
information about theADIsimPower design tools, refer to
www.analog.com/ADIsimPower. The tool set is available from
this website, and users can request an unpopulated board.
R
R
TOP
BOT
Figure 32. Simplified Peak Current Mode Control, Small Signal Circuit
V
ADP2386
OUT
ADP2386
T
Determine the cross frequency, f
f
Calculate R
R
Place the compensation zero at the domain pole, f
determine C
C
C
the ESR of the output capacitor.
C
SW
C
CP
V
C
C
CP
CP
and the optional C
/12 and f
(s) =
=
=
compensation components for ceramic output
=
is optional. It can be used to cancel the zero caused by
2
(
R
R
×
ESR
π
+
R
s
0
+
uses a transconductance amplifier for the error
–
is supported by the ADIsimPower™ design tool
g
BOT
6 .
×
×
R
R
×
m
C
SW
V
(1
ESR
C
R
, using the following equation:
V
C
R
C
C
R
OUT
/6.
by using the following equation:
BOT
C
+
1
+
×
C
C
OUT
)
+
g
R
×
R
×
m
TOP
R
C
C
V
C
C
C
×
COMP
×
OUT
OUT
C
×
CP
A
C
×
C
+
VI
C
C
CP
contribute an optional pole.
×
C
C
C
×
C
CP
f
×
−
C
C
+
–
+
s
CP
g
C
C
m
×
and C
CP
A
C
s
VI
. Generally, f
)
×
×
G
C
, contribute a zero,
VD
( )
s
C
R
OUT
ESR
ADP2386
C
is between
P
; then
V
R
C
OUT
, C
C
,