ADM1069ASTZ Analog Devices Inc, ADM1069ASTZ Datasheet - Page 13

• Manufacturer Part Number: ADM1069ASTZ
• Description: IC SUPERVISOR/SEQUENCER 32-LQFP
• Manufacturer: Analog Devices Inc
• Type: Sequencerr

Specifications of ADM1069ASTZ

• Number Of Voltages Monitored: 8
• Output: Programmable
• Voltage - Threshold: 8 Selectable Threshold Combinations
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• For Use With: EVAL-ADM1069LQEBZ - BOARD EVALUATION FOR ADM1069LQ
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Reset: -
• Reset Timeout: -

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 V
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 V
immediately turns off so that it does not pull V
V
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.
DD
capacitor can then act as a reservoir to keep the device
DD
, the synchronous rectifier switch
DD
down. The
DD
arbitrator
Rev. B | Page 13 of 32
When two or more supplies are within 100 mV of each other,
the supply that first takes control of V
example, if VP1 is connected to a 3.3 V supply, V
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.
VP1
VP2
VP3
VH
Figure 21. V
COMPARATOR
SUPPLY
DD
Arbitrator Operation
DD
IN
EN
IN
EN
IN
EN
IN
EN
keeps control. For
4.75V
4.75V
4.75V
4.75V
LDO
LDO
LDO
LDO
OUT
OUT
OUT
OUT
DD
ADM1069
VDDCAP
powers up
INTERNAL
DEVICE
SUPPLY