The LTC2937 is designed for the precise monitoring and control of load point power supplies for FPGAs, ASICs, and microprocessors, which require high accuracy and complex sequencing to prevent processor damage. The LTC2937 switches power supplies on and off in a programmable order, separated by adjustable time delays or qualifying events (e.g., power thresholds being crossed). Once sequenced, the power supply is monitored with undervoltage and overvoltage thresholds of ±0.75% accuracy. The LTC2937 provides a flexible yet accurate solution for power supply sequencing and monitoring, addressing the challenging sequencing and tolerance requirements of power supplies in computers and servers, network routers and switches, enterprise data systems, and telecommunications equipment.
The LTC2937 utilizes a unique and flexible sequencing technique, switching a power supply on or off at any of 1023 possible positions. A sequence position can be occupied by zero, one, or multiple power supplies. Empty (or reserved) sequence slots allow power sources to be added to a board design later. A simple one-wire connection synchronizes up to 50 LTC2937s, expanding sequencing to 300 sources and simplifying board routing. Multiple LTC2937s can be easily interleaved for sequencing.
An I2C/SMBus digital interface allows register configuration and reading of sequence slots and delays, control thresholds, fault response, and system status.
Thresholds are programmable to 8 bits from 0.2V to 6V in three increments, including an adjustable increment for negative power sources and for sources above 6V. Faults trigger writing to an internal EEPROM, speeding up fault analysis and debugging. The LTC2937 register can be configured through the LTpowerPlay™ development environment, eliminating the need to write software code for standalone operation. The device can be powered from a 12V intermediate bus, saving the space and cost of an external DC/DC step-down transformer. The output reset signal delay is programmable, and the reset can be disabled during voltage range testing. A regulated 3.3V output allows for level shifting to control negative sources.
Specified over the 0°C to 70°C range for commercial use and over -40°C to 85°C for industrial use, the LTC2937 is offered in a 28-pin 5mm x 6mm QFN package. Pricing starts at $6.31 per unit for orders of 1000 units. Device samples and evaluation boards are available online or from your local Linear Technology sales office.
Summary of features: LTC2937
• Time- and event-based sequencing for six sources
• Undervoltage and overvoltage monitoring for six inputs
• Guaranteed threshold accuracy of ±0.75%
• I2C/SMBus interface for configuration and register reading
• EEPROM for non-volatile configuration and logging
• Up to 50 devices can be cascaded for 300 sources
• Supported by LTpowerPlay™ GUI
• No software code required for standalone operation
• Input supply range: 2.9V to 16.5V
• Programmable output reset delay
• 28-pin 5mm x 6mm QFN package
