Electronic Components Datasheet Search
  British  ▼
ALLDATASHEET.CO.UK

X  

Preview PDF HTML

ADP5072ACBZ-R7 Datasheet(PDF) 20 Page - Analog Devices

Part # ADP5072ACBZ-R7
Description  1 A/0.6 A DC to DC Switching Regulator Independent Positive and Negative Outputs
PDF  24 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  AD [Analog Devices]
Direct Link  http://www.analog.com
Logo AD - Analog Devices

ADP5072ACBZ-R7 Datasheet(HTML) 20 Page - Analog Devices

Back Button ADP5072ACBZ-R7 Datasheet HTML 16Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 17Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 18Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 19Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 20Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 21Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 22Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 23Page - Analog Devices ADP5072ACBZ-R7 Datasheet HTML 24Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 20 / 24 page
background image
ADP5072
Data Sheet
Rev. 0 | Page 20 of 24
Inverting Regulator
The inverting converter, like the boost converter, produces an
undesirable right half plane zero in the regulation feedback loop.
This feedback loop 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 frequency is
determined by the following equation:
(1
)
2
2
LOAD2
2
Z2
2
R
DUTY
f (RHP)
π L2 DUTY
−
=
××
where:
fZ2(RHP) is the right half plane zero frequency.
RLOAD2 is the equivalent load resistance or the output voltage
divided by the load current.
NEG
DIODE2
2
IN
NEG
DIODE2
|V
| V
DUTY
V
|V
| V

+
= 

++

where VDIODE2 is the forward voltage drop of the Schottky diode
(D2).
To stabilize the regulator, ensure that the regulator crossover
frequency is less than or equal to one-tenth of the right half
plane zero frequency.
The inverting regulator loop gain is
(
2 |
|)
FB2
IN
VL2
M2
NEG
IN
NEG
OUT2
COMP2
CS2
OUT2
VV
Ag
|V
|
V
V
R
||Z
g
Z
=
×
××
+ ×
××
where:
AVL2 is the loop gain.
VFB2 is the feedback regulation voltage.
VNEG is the regulated negative output voltage.
VIN is the input voltage.
gM2 is the error amplifier transconductance gain.
ROUT2 is the output impedance of the error amplifier and is 33 MΩ.
ZCOMP2 is the impedance of the series RC network from COMP2
to AGND.
gCS2 is the current sense transconductance gain (the inductor
current divided by the voltage at COMP2), which is internally
set by the ADP5072 and is 6.25 A/V.
ZOUT2 is the impedance of the load in parallel with the output
capacitor.
To determine the crossover frequency, it is important to note
that, at that frequency, the compensation impedance (ZCOMP2) is
dominated by a resistor, RC2, and the output impedance (ZOUT2)
is dominated by the impedance of the output capacitor, COUT2.
Therefore, when solving for the crossover frequency, the equation
(by definition of the crossover frequency) is simplified to
(
2 |
|)
1
1
2
FB2
IN
VL2
M2
NEG
IN
NEG
C2
CS2
C2
OUT2
VV
Ag
|V
| V
V
Rg
πf
C
=
×
×
×
+ ×
×
×
=
×
×
where fC2 is the crossover frequency.
To solve for RC2, use the following equation:
2
(2 |
|)
C2
OUT2
NEG
IN
NEG
C2
FB2
IN
M2
CS2
π f
C
|V
| (V
V
R
V
Vg
g
×
×
×
×
+×
=
×
×
×
where GCS2 = 6.25 A/V.
Using typical values for VFB2 and GM2 results in
2
4188
|
| (
(2 |
|)
C2
OUT
NEG
IN
NEG
C2
IN
fC
V
V
V
R
V
×
×
×
×
+×
=
For improved accuracy, it is recommended to use the value of the
output capacitance, COUT2, expected for the dc bias conditions
under which it operates in the calculation for RC2.
After the compensation resistor is known, set the zero formed
by the compensation capacitor and resistor, CC2 and RC2, to one-
fourth of the crossover frequency, or
2
C2
C2
C2
C
πf
R
=
×
×
where CC2 is the compensation capacitor.
ERROR
AMPLIFIER
REF2
gM2
FB2
COMP2
RC2
CC2
Figure 45. Compensation Component



Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24


Datasheet Download

Go To PDF Page


Link URL



Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link to Datasheet    |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com