Theory Of Operation - Analog Devices AD5100 Manual

AD5100

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