EEPROM-Programmable, Quad, Power-Supply Tracker/Sequencer Circuit

Active: In Production.

The MAX6876 EEPROM-configurable, multivoltage power tracker/supervisor monitors four system voltages and ensures proper power-up and power-down conditions for systems requiring voltage tracking and/or sequencing. The MAX6876 provides a highly configurable solution as key thresholds and timing parameters are programmed through an I²C interface and these values are stored in internal EEPROM. The MAX6876 also provides supervisory functions and an overcurrent detection circuit.

The MAX6876 features programmable undervoltage and overvoltage thresholds for each input supply. When all voltages are within specifications, the device turns on the external n-channel MOSFETs to either sequence or track the voltages to the system. All of the voltages can be sequenced or tracked or powered up with a combination of the two options. During tracking, the voltage at the GATE of each MOSFET is increased to slowly turn on each supply. The voltages at the source of each MOSFET are compared to each other to ensure that the voltage differential between each monitored supply does not exceed 250mV (typ). Tracking is dynamically adjusted to force all outputs to track within a ±125mV window from a reference ramp; if, for any reason, any supply fails to track within ±250mV from the reference ramp, an active-low FAULT output is asserted, the power-up mode is terminated, and all outputs are powered off. Power-up mode is also terminated if the controlled voltages fail to complete the rampup within a programmable active-low FAULT timeout. The MAX6876 features latch-off and autoretry modes to power on again after a fault condition has been detected.

Other features of the MAX6876 include a reset circuit, a manual reset input (active-low MR), and a margin disable input (active-low MARGIN). The device also features outputs for indicating a power-good condition (PG_) and an overcurrent condition (active-low OC), and a bus-removal (REM) output.

The MAX6876 is available in a small 6mm x 6mm, 36-pin thin QFN package and is fully specified over the extended -40°C to +85°C temperature range.

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