Quad-Voltage Tracker/Sequencer Ensures Proper System Power-Up/Power-Down Operation
SUNNYVALE, CA-January 20, 2005-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX6876, an EEPROM-programmable, quad-voltage power supply tracker/sequencer. The MAX6876 monitors four voltages and ensures proper power-up and power-down conditions for systems requiring voltage tracking and/or sequencing. This highly configurable device allows key parameters such as voltage thresholds, slew rates, overcurrent limits, and timing parameters to be programmed through an I2C* interface and stored in internal EEPROM.
The MAX6876 features programmable undervoltage and overvoltage thresholds in 10mV increments for each supply input. When all voltages are within their specifications, the device turns on an external n-channel MOSFETs to track or sequence the voltages to the system. All the voltages can be tracked together, sequenced independently, or tracked and sequenced in various combinations.
During voltage tracking, the voltage at the gate of each MOSFET is increased to turn on the n-channel MOSFET. The voltage at the source of each MOSFET is measured to ensure that all voltages dynamically track to within 125mV of each other. If any supply fails to track within 250mV from the reference ramp, or if the voltage fails to power up within a specific time frame, a fault condition occurs and the power-up mode is terminated. The MAX6876 offers a fast shut-off mode to prevent power-down problems. The device incorporates independent charge pumps to ensure that each external n-channel MOSFET is fully enhanced during normal operation.
Additional features of the MAX6876 include an auto-retry (or latch-off) mode, an overcurrent-detect feature, power-good output indicators, and a reset circuit. The MAX6876 also offers a unique synchronization feature that allows up to four devices to operate in a master/slave mode and thus track up to 16 voltages.
The MAX6876 is available in a 6mm x 6mm, 36-pin TQFN and is fully specified from -40°C to +85°C. Prices start at $6.39 (1000-up, FOB USA). An evaluation kit with an easy-to-use graphical user interface is available to simplify design.
*Purchase of I2C components from Maxim Integrated Products, Inc., or one of its sublicensed Associated Companies, conveys a license under the Philips I2C Patent Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips.
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