100V micropower voltage monitors provide 1.4% accuracy for HV designs

March 27, 2015 // By Graham Prophet
LTC2965 and LTC2966 are 3.5V to 100V, single and dual channel voltage monitors that draw 6 µA of quiescent current.

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 LTC2965/LTC2966 avoid the major pitfalls of a discrete solution by integrating all components required to directly interface with high voltage rails in a 3 x 3 mm package. 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 LTC2965/LTC2966 are suited for a wide variety of applications, including battery-powered equipment, telecom systems and automotive and industrial electronics.

The LTC2965 and LTC2966 re available today in commercial, industrial and automotive versions, with operating temperature ranges from 0°C to 70°C, -40°C to 85°C, and -40°C to 125°C, respectively. The LTC2965 is offered in an 8-pin 3 x 3 mm DFN or MSOP-16 package and the LTC2966