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Single Supervisor with Watchdog Monitors Wide 0.5V to 12V Voltage Range

MILPITAS, CA – October 1, 2007 - Linear Technology Corporation introduces the LTC2917, a single voltage supervisor capable of monitoring a wide 0.5V to 12V input range. The LTC2917 can monitor 27 unique pin-selectable thresholds, ranging from a 1V drained single AA battery up to 12V industrial applications. Competitive solutions require separate supervisors for each of these different voltage thresholds. The LTC2917 VCC supply also includes a 6.2V shunt regulator for monitoring input voltages greater than 12V. The 27 selectable thresholds are specified with an overall accuracy of ±1.5% without the need of costly 0.1% external resistors to maintain accuracy.

The LTC2917 includes a watchdog input that checks whether the processor has locked up, with the option of monitoring a maximum time or a windowed time. The watchdog timer can be set to a fixed 3.2ms, 1.6s, or is adjustable based on an external capacitor, allowing the system software time to initialize. Offered in the tiny MSOP-10 and 3mm x 2mm DFN-10 packages, with guaranteed specifications across the -40°C to +125°C temperature range, the LTC2917 is ideal for automotive monitoring, portable devices, and general purpose voltage monitoring.

The LTC2917 includes two three-state input pins that select one of nine internally programmed thresholds: 12V, 5V, 3.3V, 2.5V, 1.8V, 1.5V, 1.2V, 1.0V, or an adjustable 0.5V. A third three-state input determines if the input threshold is -5%, -10% or -15% below the selected voltage level, allowing for margining. The LTC2918 is a variation on the LTC2917 that offers the same nine input thresholds, but with a fixed -5% tolerance. The LTC2918 also includes a separate manual reset input for a simple push-button interface. Both the LTC2917 and LTC2918 operate from a single 1.5V to 5.5V supply while consuming only 30uA of quiescent current.

The LTC2917 and LTC2918 are available today in commercial, industrial, and automotive temperature grades, with pricing beginning at $1.30 each, in 1,000-piece quantities.

Summary of Features: LTC2917/LTC2918 •  Monitors 9 Selectable Supplies without External Resistors:   • 12V, 5V, 3.3V, 2.5V, 1.8V   • 1.5V, 1.2V, 1.0V, +ADJ (0.5V) •  3 Selectable Tolerances :   • -5%, -10%, -15% (LTC2917) •  Manual Reset Input (LTC2918) •  Adjustable Watchdog Timeout •  Windowed Watchdog Timeout for Higher Reliability Applications (LTC2917-B1, LTC2918-B1) •  1.5V to 5.5V Supply Operation •  Guaranteed Operation to 125°C •  Guaranteed Threshold Accuracy: ±1.5% •  6.2V Shunt Regulator for High Voltage Operation •  Low Quiescent Current: 30uA •  Guaranteed #RST for VCC ≥ 0.8V •  MSOP-10 and (3mm × 2mm) DFN-10 Packages

Single Supervisor with Watchdog Monitors Wide 0.5V to 12V Range Click Photo for High-Res Image