The TPS3807 family microprocessor supervisory circuits monitor system voltages as low as 1.225V. These devices assert an open-drain RSTVDD signal when the VDD voltage drops below a preset threshold. The RSTVDD output remains asserted until the VDD voltage returns above its threshold. The device also provides an additional RSTSENSE output for a SENSE input with adjustable thresholds and hysteresis. The TPS3807 uses a precision reference to achieve 1% threshold accuracy. The TPS3807 has a very low typical quiescent current of 3.5µA, so it is well-suited to battery-powered applications. It is available in a small SC70-5 package, which is half the size of a SOT-23 package, and is fully specified over a temperature range of -40°C to +85°C.