ADM1169 Analog Devices, ADM1169 Datasheet - Page 15

• Manufacturer Part Number: ADM1169
• Description: Super Sequencer and Monitor with Margining Control and Non-Volatile Fault Recording
• Manufacturer: Analog Devices

Specifications of ADM1169

• # Supplies Monitored: 8
• Volt Monitoring Accuracy: 1%
• # Output Drivers: 8
• Fet Drive/enable Output: Both
• Voltage Readback: 12-bit ADC
• Supply Adj/margining: 12-bit ADC+4 DACs
• Package: 32 ld LQFP,40 ld LFCSP

INPUT COMPARATOR HYSTERESIS
The UV and OV comparators shown in Figure 23 are always
monitoring VPx. To avoid chatter (multiple transitions when
the input is very close to the set threshold level), these comparators
have digitally programmable hysteresis. The hysteresis can be
programmed up to the values shown in Table 6.
The hysteresis is added after a supply voltage goes out of tolerance.
Therefore, the user can program the amount above the undervoltage
threshold to which the input must rise before an undervoltage
fault is deasserted. Similarly, the user can program the amount
below the overvoltage threshold to which an input must fall
before an overvoltage fault is deasserted.
The hysteresis value is given by
where:
V
N
Note that N
hysteresis for the ranges is listed in Table 6.
INPUT GLITCH FILTERING
The final stage of the SFDs is a glitch filter. This block provides
time-domain filtering on the output of the SFD comparators,
which allows the user to remove any spurious transitions such
as supply bounce at turn-on. The glitch filter function is in addition
to the digitally programmable hysteresis of the SFD comparators.
The glitch filter timeout is programmable up to 100 μs.
Table 6. Input Functions, Thresholds, and Ranges
Input
VH
VPx
VXx
HYST
THRESH
V
is the desired hysteresis voltage.
HYST
is the decimal value of the 5-bit hysteresis code.
Function
High voltage analog input
Positive analog input
High-Z analog input
Digital input
= V
THRESH
R
× N
has a maximum value of 31. The maximum
THRESH
/255
VPx
ULTRA
LOW
LOW
MID
Voltage Range (V)
2.5 to 6.0
6.0 to 14.4
0.573 to 1.375
1.25 to 3.00
2.5 to 6.0
0.573 to 1.375
0 to 5.0
SELECT
RANGE
VREF
Figure 23. Supply Fault Detector Block
+
–
+
–
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COMPARATOR
COMPARATOR
Maximum Hysteresis
425 mV
1.02 V
97.5 mV
212 mV
425 mV
97.5 mV
Not applicable
OV
UV
For example, when the glitch filter timeout is 100 μs, any pulse
appearing on the input of the glitch filter block that is less than
100 μs in duration is prevented from appearing on the output of
the glitch filter block. Any input pulse that is longer than 100 μs
appears on the output of the glitch filter block. The output is
delayed with respect to the input by 100 μs. The filtering
process is shown in Figure 22.
FAULT TYPE
t
t
THAN GLITCH FILTER TIMEOUT
PROGRAMMED
0
0
INPUT
SELECT
TIMEOUT
INPUT PULSE SHORTER
GLITCH
FILTER
t
t
GF
GF
Voltage Resolution (mV)
13.7
32.9
3.14
6.8
13.7
3.14
Not applicable
OUTPUT
Figure 22. Input Glitch Filter Function
FAULT
OUTPUT
PROGRAMMED
THAN GLITCH FILTER TIMEOUT
t
t
0
0
TIMEOUT
INPUT PULSE LONGER
INPUT
t
t
GF
GF
OUTPUT
Glitch Filter (μs)
0 to 100
0 to 100
0 to 100
0 to 100
0 to 100
0 to 100
0 to 100
ADM1169