MAX16031 Datasheet, PDF (20/42 Pages) Maxim Integrated Products – EEPROM-Based System Monitors with Nonvolatile Fault Memory

EEPROM-Based System Monitors
with Nonvolatile Fault Memory
ABP
ILOW
IHIGH
DXP_
DXN_
-
V_BIAS ~ 100mV
+
I_BIAS
TO ADC MUX
ABP
Figure 4. Remote Temperature Sensor Amplifier Circuitry
The ADC converts the internal sensor and remote sen-
sor amplifier outputs. Each time the ADC converts all
enabled parameters, the temperature conversions are
compared to the temperature threshold registers (r46h
to r4Bh and r4Dh). Unlike the voltage input compara-
tors, the temperature threshold comparators are 10 bits
wide. OVERT is the designated output for temperature
faults, although other outputs are programmed to
depend on temperature faults as well. See the
Programmable Inputs/Outputs section for more informa-
tion on programming output dependencies. See the
Faults section for more information on setting tempera-
ture fault thresholds.
The remote temperature sensor amplifier detects a
short or open between DXP_ and DXN_. The detection
of these events is programmed to cause a fault.
Temperature thresholds and conversions are in a two’s
complement temperature format, where 1 LSB corre-
sponds to 0.5°C. The data format for temperature con-
versions is illustrated in Table 5.
Offset and gain errors for remote temperature sensor
measurements are user-trimmed through gain registers
r19h[7:2]/r4Fh[5:0] and offset registers r1Bh[7:5]/r4D[6:4],
as shown in Tables 4 and 6. The gain value trims the
high (56µA) drive current source to compensate for the
n-factor of the remote diode. The offset value is multi-
plied by 4 and added to the conversion result numeri-
cally. The MAX16031/MAX16032 contain an internal
lowpass filter at DXN_ and DXP_ to reduce noise. See
the Miscellaneous Settings section for more information
on programming the filter cutoff frequency.
Table 5. Temperature Data Format
TEMPERATURE (°C)
+128
+125
+100
+25.5
0
-10
-75
-100
-128
Diode fault
DIGITAL CODE
1100000000
1011111010
1011010000
1000110011
1000000000
0111101100
0101101010
0100111000
0100000000
0000000000
Reading ADC Results
ADC conversion results are read from the ADC conver-
sion registers through the I²C/SMBus-compatible or
JTAG interfaces (see Table 7). These registers are also
used for fault threshold comparison. Voltage monitoring
thresholds are compared with only the first 8 MSBs of
the conversion results.
Programmable Inputs/Outputs
The MAX16031 provides two general fault outputs,
FAULT1 and FAULT2, one reset output RESET, one
temperature fault output OVERT, one current fault out-
put OVERC, two general-purpose inputs/outputs GPIO1
and GPIO2, and one SMBALERT#-compatible output
ALERT. The MAX16032 provides the same except
OVERC. All outputs are open drain and require pullup
resistors. Fault outputs do not latch except for OVERC,
which either latches or does not latch depending on the
configuration bit in r5Ch. Individual fault flag bits, how-
ever, latch (see the Faults section) and must be cleared
one bit at a time by writing a byte containing all zeros
except for a single ‘1’ in the bit to be cleared.
The general outputs, FAULT1 and FAULT2, are identi-
cal in functionality and are programmed to depend on
overvoltage, undervoltage, overtemperature, and over-
current parameters. See r1Dh and r1Eh in Table 8 for
more detailed information regarding the general fault
output dependencies.
The reset output RESET provides many programmable
output dependencies as well as reset timeouts. See
r20h and r21h in Table 8 for detailed information on
RESET output dependencies and timeouts.
The temperature fault output OVERT indicates tempera-
ture-related faults. OVERT is programmed to depend
on any primary temperature threshold and/or the
remote diode open/short flags. OVERT latches low dur-
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