Voltage monitors preserve critical system data

Preserving critical system data in nonvolatile memory lets customers identify a failing voltage rail and isolate the cause of board failures during test debug or failure analysis.

Maxim Integrated Products has released the MAX16046-MAX16049, 12/8-channel, EEPROM-configurable, voltage sequencers/monitors/marginers.

These devices use nonvolatile fault registers to store system voltage and fault information upon a critical system failure.

Preserving critical system data in nonvolatile memory lets customers identify a failing voltage rail and isolate the cause of board failures during test debug or failure analysis.

These devices sequence, reverse sequence, monitor and margin up to 12 supplies (MAX16046/MAX16047) or eight supplies (MAX16048/MAX16049).

The principal applications for the MAX16046-MAX16049 are high-reliability systems such as storage, telecom, or networking equipment where a large number of voltage rails exist in a single system.

Historically, the more complex the application, the more convoluted the monitoring system required.

Customers typically used several discrete devices to monitor onboard system conditions.

These devices were numerous and spread across the board, which consumed valuable board space.

Additional hardware was needed for timeout delays and programming.

All this led to higher costs and longer development time.

The MAX16046-MAX16049 greatly simplify this system-monitoring function.

A high-performance ADC eliminates the need for discrete comparators.

The internal, 1% accurate ADC measures each input voltage and compares the result to one upper, one lower and one selectable upper or lower threshold limit.

Users benefit because this precision and high speed provides a faster response time.

Users would have typically needed 36 external comparators to monitor two undervoltage and one overvoltage thresholds for a 12-channel system.

As a result of the MAX16046-MAX16049's high integration, more board space is saved and costs further reduced.

Margining system voltages is an effective means of stress testing high-reliability systems.

This feature is especially important for applications where field failures are unacceptable.

Now manufacturers can identify premature failures during the manufacturing process, so their customers are not disrupted and costly returns are avoided.

The 12/8 DAC outputs of the MAX16046/MAX16048 devices are under I2C or logic input control and make it easy to implement power-supply voltage margining during the development phase, qualification phase and production test.

The DAC outputs are connected to the feedback node or trim input of the power supplies.

A margining calculator is included in the configuration GUI program to facilitate resistor and DAC value calculations.

Highly complex system controllers require precise power-up and power-down voltage sequencing.

In the past, board layouts were fixed and these layouts were time-consuming and extremely expensive to change.

In addition, it was notoriously difficult, if not impossible, to both sequence and reverse-sequence power supplies with the same topology.

Customers can avoid these problems with the MAX16046-MAX16049, because the new devices dynamically sequence up and reverse sequence in any order.

The MAX16046-MAX16049 also have integrated charge pumps and a voltage ramp generator that can be used to track up to four system voltages in a closed-loop system.

The devices charge the gate of a series-pass nMOSFET with a controlled ramp rate to power up the system voltages, all tracking within 250mV.

Users will benefit because they now can control power-up and power-down for mixed-mode (sequencing/tracking) systems.

Internal EEPROM stores the chip configuration.

The configuration is copied to working registers on power-up.

The devices are also configurable on-the-fly through the I2C-/SMBus-compliant or JTAG standard interfaces.

The EEPROM is in-circuit programmable over both the JTAG and I2C interfaces.

Multipurpose GPIOs are another desirable feature of the MAX16046-MAX16049.

These GPIOs are EEPROM-configurable as dedicated fault outputs, a watchdog input or output, a manual reset, or as margin-control inputs.

These flexible GPIOs save pin count, another means of reducing board space.

The MAX16046-MAX16049 have a 3 to 14V operating voltage range.

They can be powered directly from a 12V intermediate bus, reducing the number of external components required.

The MAX16046-MAX16049 are fully specified over the -40 to +85C extended temperature range.

The devices are offered in a 56-pin, 8 x 8mm TQFN package.

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