AD5100
Rev. A | Page 12 of 36
THEORY OF OPERATION
The AD5100 is a programmable system management IC that
has four channels of monitoring inputs. Three inputs have
high voltage (30 V) capability. For example, if the AD5100 is
used in an automotive application, V
1MON
(Monitoring Input 1)
can be connected to the battery and the V
2MON
can be connected
to the ignition switch, a rising edge trigger wake-up signal, or
the media-oriented systems transport (MOST) wake-up signal
(V
4MON
is connected to V
2MON
for MOST applications). Two
other inputs, V
3MON
and V
4MON
, are designed for low voltage
monitoring, with programmable thresholds from 2.93 V to
7.96 V. The two high voltage monitoring inputs control the
shutdown signal, SHDN and reset signal, RESET, while the two
low voltage monitoring inputs control the reset signal, RESET.
SHDN and RESET are both disabling signals for external devices.
The differences between these two outputs are in output level
and driving capabilities, as described in the
section.
The WDI (watchdog) and
MR (manual reset) inputs also
control the RESET output, for use with an external digital
processor.
shows the general flow chart and
summarizes the AD5100 functions and features.
05
69
2-
00
5
YES
NO
SHDN = 0*
SHDN = 0
RESET = 0
RESET = 0
RESET = 0
RESET = 0
RESET = 0
YES
NO
SHDN = 0*
V
1MON
> UV
V
1MON
< OV
YES
YES
NO
SHDN = 0
NO
SHDN = 0
SHDN = 1
V
2MON
> ON
V
2MON
> OFF
(V
2MON
RISING EDGE
SENSITIVE SELECTED)
V
2MON
LEVEL
SENSITIVE
SELECTED
YES
NO
CONTINUE
MONITORING
NO
YES
V
4MON
>
THRESHOLD
V
4OUT
= 0
V
4OUT
= 1
NO
YES
USING V
4OUT
FOR PWM
NO
YES
V
4MON
>
THRESHOLD
NO
YES
V
3MON
>
THRESHOLD
YES
NO
VALID WDI
YES
NO
VALID WDI
NO
YES
FLOATING
WDI DISABLED
YES
STANDARD
WDI SELECTED
YES
NO
MR = 1
RESET = 0
YES
NO
FLOATING WDI
NO (ADVANCE WDI SELECTED)
* SEE TABLE 11 RESET CONFIGURATION REGISTER:
IF [0] = 0, THEN SHDN = 0 AND RESET = 0
IF [0] = 1, THEN SHDN = 0 AND RESET = 1
DEFAULT PATHS
Figure 5. General Flow Chart
Table 10. AD5100 Functions and Features
Input
Monitoring
Range
Shutdown
Control
Reset
Control
Fault
Detection
Functions and Features
If Not Used
V
1MON
6 V to 28.29 V
Yes
Yes
Yes
Overvoltage/undervoltage thresholds
Does not apply
V
2MON
3 V to 24.75 V
Yes
Yes
Yes
On/off voltage thresholds; pseudo rising edge
triggered, wake-up selectable; MOST wake-up
signal (V
2MON
connected to V
4MON
)
Connect to V
1MON
,
minimum input 6 V
V
3MON
2.32 V to 4.97 V
No
Yes
Yes
Connect to V
OTP
and
set threshold to
minimum
V
4MON
1.67 V to 7.96 V
No
Yes
Yes
Additional output
Connect to GND
WDI
0 V to 5 V
Yes
Yes No
Standard, advance, or floating; watchdog
selectable
Leave floating
MR
0 V to 5 V
Yes
Yes No
Highest priority on RESET over other inputs
Leave floating