The SMS66 from Summit Microelectronics is a 6-channel programmable power-supply sequencer with a rich set of monitoring and housekeeping functions. Typical applications for the device include server, networking and communications equipment where carrier-class availability (i.e., 99.999% up-time) is required.
The SMS66 is user-configurable to sequence as many as six voltage supplies in any order during both power-up and power-down transitions. This sequencing can be set to cascade each supply once the prior supply completes its transition, therefore relieving the user of the need to estimate the slew rate of each supply voltage. Furthermore, users can select one of several delay times before that supply is actuated, guaranteeing that unwanted supply crossover doesn’t occur.
The SMS66 monitors Vdd (2.7V to 5.5V), a second "high supply" (7V to 15V), two external general-purpose analog signals, and the internal chip temperature, all to 10-bit precision. Such precision (5 mV steps) is more than adequate to handle the tightening accuracy requirements of ever-reducing supply voltages. Any of these five signals can be set to generate fault reporting and if desired, a reset with either an orderly sequenced or an immediate forced shutdown of all supplies.
Reset can also be generated in the event of a power-up stall of programmable duration. Finally, the SMS66 allows external use of the ±0.6% on-chip voltage reference.
The SMS66 is accessed using the popular I2C bus to exercise complete control of the board's power characteristics. This can be programmed during production, or each time the board is booted up, or during normal operation on the fly.
For more information, visit www.summitmicro.com.