Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

NCP5425DBR2G Datasheet(PDF) 12 Page - ON Semiconductor

Part # NCP5425DBR2G
Description  Dual Synchronous Buck Controller
Download  22 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  ONSEMI [ON Semiconductor]
Direct Link  http://www.onsemi.com
Logo ONSEMI - ON Semiconductor

NCP5425DBR2G Datasheet(HTML) 12 Page - ON Semiconductor

Back Button NCP5425DBR2G Datasheet HTML 8Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 9Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 10Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 11Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 12Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 13Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 14Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 15Page - ON Semiconductor NCP5425DBR2G Datasheet HTML 16Page - ON Semiconductor Next Button
Zoom Inzoom in Zoom Outzoom out
 12 / 22 page
background image
NCP5425
http://onsemi.com
12
Figure 8A − Basic Current Sensing
Represents a basic inductor sensing configuration. When
the voltage at pin +Is exceeds the voltage at pin –Is by 70 mV
(nominal), the internal current sense comparator offset will
be overcome. For this case, the current limit threshold is
equal to (70 mV/Rx) amps. An obvious disadvantage of the
basic configuration is the power supply designer has no
control over the 70 mV offset, and limited control over the
value of Rx. Therefore, he or she has little flexibility to set
a specific current limit. Configurations (8B) and (8D) depict
techniques to increase and decrease, respectively, the
threshold current.
Figure 8B – Increasing the Current Threshold
Addition of resistor R2 forms a voltage divider such that
only a portion of the voltage across Rx appears across C1.
If, for example, R1 = R2, it will require a 140 mV drop
across Rx to overcome the internal 70 mV current sense
comparator offset. For optimum compensation with this
configuration, R1 and R2 should be selected such that Rx is
equal to their equivalent parallel resistance.
Figure 8C – Bias Current Compensation
Configurations 8A, 8B and 8D all introduce a potential
error, since the bias currents of the current sense comparator
inputs flow through unbalanced resistance paths. The
addition of R3 in configuration 8C, where R3 = R1, restores
a balanced input resistance, such that any voltage drops
introduced by bias currents will cancel (assuming the +Is
and –Is bias currents are equal). In the case of configuration
8B, R3 would be made equal to the equivalent resistance of
R1 and R2 in parallel.
Figure 8D – Decreasing the Current Threshold
A voltage divider comprised of R3 and R4 is introduced
to develop, by scaling the output voltage, a small voltage
drop across R3 that opposes the internal current sense
comparator offset. For example, if Vout = 1.2 V, R3 = 200
W,
and R4 = 11.8 K, a DC voltage drop of 20 mV will be
established across R3. The polarity of that voltage is such
that it opposes the internal 70 mV offset, effectively
reducing it to 50 mV. The current threshold is now given by
(50 mV/Rx) instead of (70 mV/Rx).
Current Limiting
Both channels of the NCP5425 employ identical
Cycle−by−Cycle current limiting. Comparators with
internal 70 mV offsets provide the references for setting
current limit. Once a voltage greater than 70 mV is applied
to the current limiting comparator, it resets that channel’s
output RS flip flop. This terminates the PWM pulse for the
cycle and limits the energy delivered to the load. One
advantage of this current limiting scheme is that the
NCP5425 will limit large transient currents yet resume
normal operation on the following cycle. A second benefit
of limiting the PWM pulse width is, in an input power
sharing application, one controller can be current limiting
while the other supplies the remaining load current.
Output Enable
On/Off control of the regulator outputs can be
implemented by pulling the COMP pins low. Driving the
COMP pins below the 0.20 V PWM comparator offset
voltage disables switching of the GATE drivers.


Similar Part No. - NCP5425DBR2G

ManufacturerPart #DatasheetDescription
logo
ON Semiconductor
NCP5425DBR2G ONSEMI-NCP5425DBR2G Datasheet
178Kb / 22P
Dual Synchronous Buck Controller
July, 2006 ??Rev. 9
NCP5425DBR2G ONSEMI-NCP5425DBR2G Datasheet
172Kb / 22P
Dual Synchronous Buck Controller
July, 2006 ??Rev. 9
More results

Similar Description - NCP5425DBR2G

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM2647 NSC-LM2647 Datasheet
763Kb / 25P
Dual Synchronous Buck Regulator Controller
logo
Sipex Corporation
SP6134HV SIPEX-SP6134HV Datasheet
141Kb / 14P
Dual Supply Synchronous Buck Controller
SP6137HV SIPEX-SP6137HV Datasheet
265Kb / 13P
Dual Supply Synchronous Buck Controller
logo
ON Semiconductor
NCP5425 ONSEMI-NCP5425 Datasheet
155Kb / 22P
Dual Synchronous Buck Controller
January, 2005 ??Rev. 6
logo
Semtech Corporation
SC415 SEMTECH-SC415 Datasheet
927Kb / 30P
Dual Synchronous Buck Controller
SC415 SEMTECH-SC415_08 Datasheet
763Kb / 30P
Dual Synchronous Buck Controller
logo
ON Semiconductor
NCP5425SOEVB ONSEMI-NCP5425SOEVB Datasheet
178Kb / 22P
Dual Synchronous Buck Controller
July, 2006 ??Rev. 9
logo
Texas Instruments
LM2647 TI1-LM2647 Datasheet
3Mb / 43P
Dual Synchronous Buck Regulator Controller
logo
ON Semiconductor
NCP5424A ONSEMI-NCP5424A Datasheet
134Kb / 20P
Dual Synchronous Buck Controller
August, 2003 ??Rev. 0
NCP5425 ONSEMI-NCP5425_09 Datasheet
172Kb / 22P
Dual Synchronous Buck Controller
July, 2006 ??Rev. 9
More results


Html Pages

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


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   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