MAX16070 Datasheet, PDF(12/52 Page) Maxim Integrated Products – 12-Channel/8-Channel, Flash-Configurable System Monitors with Nonvolatile Fault Registers

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12-Channel/8-Channel, Flash-Configurable System

Managers with Nonvolatile Fault Registers

When in the monitoring state, a register bit, ENRESET,

is set to a â1â when EN falls below the undervoltage

threshold. This register bit latches and must be cleared

through software. This bit indicates if RESET asserted

low due to EN going under the threshold. The POR state

of ENRESET is â0â. The bit is only set on a falling edge

of the EN comparator output or the software enable bit.

Voltage/Current Monitoring

The MAX16070/MAX16071 feature an internal 10-bit

ADC that monitors the MON_ voltage inputs. An internal

multiplexer cycles through each of the enabled inputs,

taking less than 40Fs for a complete monitoring cycle.

Each acquisition takes approximately 3.2Fs. At each

multiplexer stop, the 10-bit ADC converts the analog

input to a digital result and stores the result in a register.

ADC conversion results are stored in registers r00h to

r1Ah (see Table 6). Use the SMBus or JTAG serial inter-

face to read ADC conversion results.

The MAX16070 provides twelve inputs, MON1 to MON12,

for voltage monitoring. The MAX16071 provides eight

inputs, MON1 to MON8, for voltage monitoring. Each

input voltage range is programmable in registers r43h to

r45h (see Table 5). When MON_ configuration registers

are set to â11,â MON_ voltages are not monitored, and

the multiplexer does not stop at these inputs, decreasing

the total cycle time. These inputs cannot be configured

to trigger fault conditions.

The three programmable thresholds for each monitored

voltage include an overvoltage, an undervoltage, and a

secondary warning threshold that can be set in r73h[3]

to be either an undervoltage or overvoltage threshold.

See the Faults section for more information on setting

overvoltage and undervoltage thresholds. All voltage

thresholds are 8 bits wide. The 8 MSBs of the 10-bit ADC

conversion result are compared to these overvoltage

and undervoltage thresholds.

Inputs that are not enabled are not converted by the

ADC; they contain the last value acquired before that

channel was disabled.

The ADC conversion result registers are reset to 00h at

boot-up. These registers are not reset when a reboot

command is executed.

Configure the MAX16070/MAX16071 for differential

mode in r46h (Table 5). The possible differential pairs

are MON1/MON2, MON3/MON4, MON5/MON6, MON7/

MON8, MON9/MON10, MON11/MON12 with the first

input always being at a higher voltage than the second.

Use differential voltage sensing to eliminate voltage off-

sets or measure supply current. See Figure 3. In differ-

ential mode, the odd-numbered MON_ input measures

the absolute voltage with respect to GND while the result

of the even input is the difference between the odd and

even inputs. See Figure 3 for the typical differential mea-

surement circuit.

POWER

SUPPLY

POWER

SUPPLY

ILOAD

MONODD

MONEVEN

MAX16070

MAX16071

MONODD

MONEVEN

LOAD

VMON

CSP

CSM

RSENSE

LOAD

MAX16070

TO ADC MUX

*AV

OVERC

*VCSTH

*ADJUSTABLE BY r47h [3:2]

Figure 3. Differential Measurement Connections

Figure 4. Current-Sense Amplifier

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