Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

ADM1069ASTZ Datasheet(PDF) 13 Page - Analog Devices

Part No. ADM1069ASTZ
Description  Super Sequencer with Margining Control
Download  32 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  AD [Analog Devices]
Homepage  http://www.analog.com
Logo 

ADM1069ASTZ Datasheet(HTML) 13 Page - Analog Devices

Zoom Inzoom in Zoom Outzoom out
 13 / 32 page
background image
ADM1069
Rev. C | Page 13 of 32
POWERING THE ADM1069
The ADM1069 is powered from the highest voltage input on
either the positive-only supply inputs (VPx) or the high voltage
supply input (VH). This technique offers improved redundancy
because the device is not dependent on any particular voltage rail
to keep it operational. The same pins are used for supply fault
detection (see the Supply Supervision section). A VDD arbitrator
on the device chooses which supply to use. The arbitrator can
be considered an OR’ing of four low dropout regulators (LDOs)
together. A supply comparator chooses the highest input to
provide the on-chip supply. There is minimal switching loss
with this architecture (~0.2 V), resulting in the ability to power
the ADM1069 from a supply as low as 3.0 V. Note that the
supply on the VXx pins cannot be used to power the device.
An external capacitor to GND is required to decouple the on-
chip supply from noise. This capacitor should be connected to
the VDDCAP pin, as shown in Figure 21. The capacitor has
another use during brownouts (momentary loss of power).
Under these conditions, when the input supply (VPx or VH)
dips transiently below VDD, the synchronous rectifier switch
immediately turns off so that it does not pull VDD down. The
VDD capacitor can then act as a reservoir to keep the device
active until the next highest supply takes over the powering
of the device. A 10 μF capacitor is recommended for this
reservoir/decoupling function.
The VH input pin can accommodate supplies up to 14.4 V, which
allows the ADM1069 to be powered using a 12 V backplane supply.
In cases where this 12 V supply is hot swapped, it is recommended
that the ADM1069 not be connected directly to the supply. Suitable
precautions, such as the use of a hot swap controller, should be
taken to protect the device from transients that could cause
damage during hot swap events.
When two or more supplies are within 100 mV of each other,
the supply that first takes control of VDD keeps control. For
example, if VP1 is connected to a 3.3 V supply, VDD powers up
to approximately 3.1 V through VP1. If VP2 is then connected
to another 3.3 V supply, VP1 still powers the device unless VP2
goes 100 mV higher than VP1.
SUPPLY
COMPARATOR
IN
EN
OUT
4.75V
LDO
IN
EN
OUT
4.75V
LDO
IN
EN
OUT
4.75V
LDO
IN
EN
OUT
4.75V
LDO
VH
VP3
VP2
VP1
VDDCAP
INTERNAL
DEVICE
SUPPLY
Figure 21. VDD Arbitrator Operation


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  25  26  27  28  29  30  31  32 


Datasheet Download




Link URL




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

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