EVAL-AD5100EBZ View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
EVAL-AD5100EBZ
Analog Devices
'EVAL-AD5100EBZ' PDF : 36 Pages View PDF
AD5100
V1MON
tGLITCH
V2MON
t1SD_DELAY*
t1SD_DELAY*
SHDN
AND RESET
t2SD_HOLD*
t1SD_HOLD*
t1SD_HOLD*
tFD_DELAY
tFD_DELAY
tGLITCH
tMIN#
t2SD_HOLD*
t2SD_DELAY*
tFD_DELAY
V1MON_OV*
V1MON_UV*
V2MON_ON*
V2MON_OFF*
t2SD_DELAY*
tFD_DELAY
SHDNWARN
NOTES
1. * = PROGRAMMABLE.
2. # = THE DURATION OF THE tMIN MUST BE SHORTER THAN tVREG_OFF_DELAY OR ELSE THE AD5100 WILL BE POWERED OFF.
Figure 7. V1MON and V2MON Shutdown Timing Diagrams in Level-Sensitive Mode (Note that RESET Follows SHDN)
V2MON
V2MON_ON
V2MON is a high voltage monitoring input that controls the SHDN
and RESET functions of the external devices. V2MON monitors
inputs from 3 V to 30 V. It has a 16-level programmable turn-on
and turn-off (on, off) hysteresis thresholds (Register 0x03 and
Register 0x04), with an 8-step 0.07 ms to 200 ms shutdown hold
time (t2SD_HOLD) and 0.07 ms to 1200 ms shutdown delay
(t2SD_DELAY).
The V2MON pin is monitored by two comparators, one for turn-
on and one for turn-off detection, in the level-sensitive power-
up mode. Both are designed with 1.5% hysteresis. Only the
turn-on monitoring comparator is used if the rising edge
triggered wake-up mode is selected.
V2MON
HYSTERESIS
V2MON_OFF
HYSTERESIS
ON
ON
COMPARATOR COMPARATOR
ACTIVE
INACTIVE
OFF
OFF
COMPARATOR COMPARATOR
ACTIVE
INACTIVE
Figure 8. V2MON Hysteresis
By default, V2MON is level sensitive and the on and off thresholds
are both monitored. The on threshold chosen must be greater
than the off threshold.
When the V2MON input goes above the programmed V2MON on
threshold, the comparator becomes active immediately, indicat-
ing that an on condition has occurred. Due to hysteresis, the
V2MON input must be brought below the programmed threshold
by 1.5% before the comparator becomes inactive, indicating that
the on condition has gone away (see Figure 8).
When the V2MON input drops below the programmed threshold,
the comparator becomes active immediately, indicating that a
V2MON off condition has occurred. Similarly, due to hysteresis,
the V2MON input must be brought above the programmed threshold
by 1.5% before the comparator becomes inactive, indicating that
the off condition has gone away.
When the SHDN output is activated by the input reaching
the V2MON_OFF threshold, such fault condition is temporarily
recorded in the fault detection register. The SHDNWARN
output transitions low for signaling before the shutdown output,
SHDN, activates. The timing of the SHDN output is dependent
on how long the shutdown programmed delay (t2SD_DELAY) is set
relative to the SHDNWARN propagation delay (tFD_DELAY ). This
feature allows the system to finish any critical housekeeping
tasks before shutting down the external device. SHDN activates
once the voltage on V2MON is outside the threshold for a time longer
than tGLITCH. RESET follows SHDN delay and hold timings when
triggered by V2MON.
The V2MON, shutdown, and shutdown warning timing diagrams
are shown in Figure 7.
Rev. A | Page 14 of 36
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