Voltage monitors provide a 1.4% accuracy

26th March 2015

Siobhan O'Gorman

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The LTC2965 and LTC2966, 3.5V to 100V, single and dual channel voltage monitors that draw only 6µA of quiescent current have been released by Linear Technology. Alternative voltage monitoring solutions typically call for a low power comparator, a high input voltage LDO to power the comparator and a high value resistive divider to level translate the monitored rail, all of which increase board space and power consumption, and decrease monitoring accuracy.

The voltage monitors avoid the major pitfalls of a discrete solution by integrating all components required to directly interface with high voltage rails in space-efficient 3x3mm packages. Each device includes resistor-programmable threshold inputs to facilitate simple undervoltage, overvoltage or window monitoring of positive or negative rails to within ±1.4% accuracy over temperature.

In addition to the high voltage inputs, the LTC2965/LTC2966 include adjustable-polarity UV/OV comparator outputs that can be pulled up to voltages as high as 100V. All high voltage pins are rated to 140V, withstanding high voltage transients without damage. Integrated high value resistive dividers with selectable ratios offer improved accuracy, power savings and flexibility compared to solutions using external high value resistors. Threshold programming is achieved using low value discrete resistors in combination with configuration pins for scaling the comparator thresholds and setting output polarity. A built-in buffered reference provides convenient low voltage biasing for the external resistive dividers. High and low threshold input pins provide for a flexible and wide hysteresis range by simply setting a different voltage on each pin. If the hysteresis value is not critical, one of the inputs can be grounded to select an internal default hysteresis voltage. The small size, wide operating range and low power consumption of the voltage monitors are suitable for a wide variety of applications, including battery-powered equipment, telecomms systems and automotive and industrial electronics.

The LTC2965 and LTC2966 are available now in commercial, industrial and automotive versions, with operating temperature ranges from 0 to +70°C, -40 to +85°C, and -40 to +125°C, respectively. The LTC2965 is offered in an 8-pin 3x3mm DFN or MSOP-16 package and the LTC2966 is offered in a 16-pin 3x3mm QFN or 20-lead SO package. The LTC2965 is priced from $1.98, while the LTC2966 starts at $2.44. Both voltage monitors are sold in 1,000-piece quantities.