AD8280WASTZ Analog Devices Inc, AD8280WASTZ Datasheet - Page 21

• Manufacturer Part Number: AD8280WASTZ
• Description: Lithium Ion Battery Safety Monitor
• Manufacturer: Analog Devices Inc

Specifications of AD8280WASTZ

• Function: Battery Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 6 V ~ 30 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Self-Test and Alarm Conditions
If an alarm occurs just prior to or just after the self-test pulse is
initiated, the alarm causes the self-test to fail. The time span for
this condition depends on the deglitch time.
•
•
Therefore, in the unusual circumstance that the part fails self-
test and there is an alarm condition state after the self-test, it
is recommended that the user retest the part to ensure that
an alarm did not occur just prior to or just after initiating the
self-test.
The self-test works when the part is in the shared alarm mode
or in the separate alarm mode. When the part is in the separate
alarm mode, the self-test status on an output pertains only to
that portion of the internal circuit relevant to the condition being
monitored: overvoltage, undervoltage, or overtemperature.
Deglitch time = 0.0 sec. The part fails self-test if an alarm
occurs in the time period from 20 ms before the leading
edge of the self-test pulse to 20 ms after the leading edge
of the self-test pulse.
Deglitch time > 0.0 sec. The part fails self-test if an alarm
occurs in the time period from 120 ms before the leading
edge of the self-test pulse to 120 ms after the leading edge
of the self-test pulse.
AIOUTxx/AVOUTxx
AIOUTxx/AVOUTxx
AIOUTxx/AVOUTxx
AIOUTxx/AVOUTxx
AIOUTxx/AVOUTxx
NORMAL OPERATION
DURING SELF-TEST MODE
TEST FAILS
ALARMED
TEST OK
TEST OK
UNALARMED
ALARMED
TESTI
Figure 51. Timing Diagram for Alarms at AIOUTxx and AVOUTxx
Rev. A | Page 21 of 24
HIGH AT FALLING EDGE OF TESTI:
PART FAILS SELF-TEST
Self-Test Timing and Monitoring Strategy
When monitoring the signals for self-test on the AD8280, note
the following items:
•
•
•
•
After initiating a self-test of the AD8280 with a rising edge
on the TESTI pin, the alarm appearing at the AVOUTxx
pin remains valid up to t
When the rising edge of the TESTI pulse occurs, the user
should monitor the AVOUTxx pin to make sure that it is
in the high state after the t
After the t
the AVOUTxx pin has changed to the low state, indicating
that the part or parts passed the self-test. The user must
also ensure that the minimum length of the TESTI pulse
is greater than t
AVOUTxx pin is valid until t
of the TESTI pulse.
The alarm state is valid again t
of the pulse.
ST
max time has elapsed, the user can verify that
ST
max. The status of the self-test on the
LOW AT FALLING EDGE OF TESTI:
PART PASSES SELF-TEST
RE
RE
max.
max time has elapsed.
STV
FE
min after the trailing edge
max after the trailing edge
AD8280