100V Micropower Voltage Monitor Configure High Voltage Designs for 1.4% Accuracy The LTC®2965 (single) and LTC2966 (dual) high voltage monitors feature a wide operating range, low power consumption and configurable input/outputs. 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. Integrated high value resistive dividers with selectable gain offer improved accuracy and flexibility compared to solutions using external high value resistors. Features nn nn nn nn nn nn nn nn nn Wide Operating Range: 3.5V to 100V Quiescent Current: 7µA Typical Adjustable Threshold Range Internal High Value Resistive Dividers 1.4% Accuracy Over Temperature Adjustable Output Polarity High Voltage Rated Outputs Adjustable or Built-In Hysteresis Guaranteed Operation to 125°C Product Selection Part Number Number of Channels 1 3mm × 3mm DFN-8, MSOP-16 LTC2966 2 3mm × 3mm QFN-16, SO-20 LTC2965 L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Packages Application Examples 5V –48V SUPPLY MONITOR RISING THRESHOLD –40.2 FALLING THRESHOLD –36.2 HYSTERESIS –4.0 GAIN 40x Single –48V UV Monitor In this circuit, the LTC2965’s inverting-configured output forces a UV pin to pull to 5V when the –48V input supply drops below –36V. The 100V OUT pin allows the LTC2965 to drive an opto-coupler to translate the undervoltage signal to the 5V system. 100k UV 5V SYS 4.2mA AT –48V RTN 1k VIN RS REF 140k 1000pF 10V INH LTC2965 10k OUT 10k INL 90.9k PS GND –48V 48V OV/UV MONITOR CHANNEL RISING THRESHOLD FALLING THRESHOLD HYSTERESIS GAIN 48V UV and OV Monitor In this circuit, the LTC2966 provides window detection, where Channel A monitors for a 36V UV condition and Channel B monitors for a 72V OV condition. If either threshold is exceeded, the system’s UV or OV output pulls to 5V. Connecting INHA and INLB to ground enables internal hysteresis for each channel in the appropriate direction and reduces the number of external components. A 36.5 36.1 0.4 20x 48V VINA VINB REF 1000pF 10V RS1A RS2A RS1B RS2B INHA 294k LTC2966 887k 100k 100k UV OV PSA GND 5V SYS OUTB PSB 12V AUTOMOTIVE BATTERY UV/OV INDICATOR CHANNEL A RISING THRESHOLD 9.2 FALLING THRESHOLD 9.0 HYSTERESIS 0.2 GAIN 10x 12V Battery UV and OV Monitor 5V OUTA INLA INHB INLB In this circuit, the LTC2966 provides window detection for a vehicle battery, where the detection window is configured to be ±25% of the nominal 12V battery voltage. Channel A monitors for an OV condition and Channel B monitors for a UV condition. By connecting the LTC2966’s outputs together, FAULT is pulled low if either threshold is exceeded. The LTC2966 also tolerates load dump voltage transients >72V without additional components. B 72.1 71.3 0.8 40x B 15.0 14.8 0.2 10x 12V VEHICLE BATTERY 1000pF 10V VINA REF 453k 300k INHA INLA 453k INLB INHB VINB RS1A RS2A RS1B RS2B LTC2966 GND OUTA PSA OUTB PSB 5V 100k FAULT 5V SYS www.linear.com/2965 n 1-800-4-LINEAR 0115