Supervisory circuit from Diodes monitors system voltage with programmable delay
The PT7M3808 family of microprocessor supervisory circuits monitors system voltages from 0.4 to 5.0V. With threshold accuracy from 0.5 per cent and an adjustable delay time from 1.25 to 10ms, these small form-factor devices enable power-on reset functionality for microprocessor and other digital systems while consuming minimal power, says Diodes. Applications include notebook and desktop computers, and battery-powered portable equipment for markets ranging from data centres to security systems.
Offered in fixed-threshold versions for standard voltage rails between 0.9 and 5.0V, and with an adjustable threshold version down to 0.4V, the PT7M3808 uses a precision reference to provide a 0.5 per cent negative-going input threshold accuracy when monitoring voltages up to 3.3V and one per cent accuracy at voltages from 3.3 to 5.0V. The delay time is adjusted from 1.25 to 10ms by connecting an external capacitor to the CT pin. A longer 20ms delay can be achieved by disconnecting the CT pin, while a 300ms delay is possible by connecting the CT pin to VDD with a resistor, advises Diodes.
The PT7M3808 has a very low quiescent current, typically 2.8A, making it suited to battery-powered applications. Available in space-conscious SOT26 and DFN2020-6 packages, the PT7M3808 takes up very little board space for both new and drop-in replacement designs, says Diodes.
Diodes manufactures and supplies application specific standard products within the broad discrete, logic, analogue and mixed-signal semiconductor markets. Diodes serves the consumer electronics, computing, communications, industrial, and automotive markets with its product portfolio of diodes, rectifiers, transistors, MOSFETs, protection devices, function-specific arrays, single gate logic, amplifiers and comparators, Hall-effect and temperature sensors, power management devices, including LED drivers, AC/DC converters and controllers, DC/DC switching and linear voltage regulators, and voltage references along with special function devices, such as USB power switches, load switches, voltage supervisors, and motor controllers. The company’s headquarters are in Plano, Texas, with sales office in Milpitas, California, USA. Design, marketing, and engineering centres are in Plano, Milpitas, Taipei, Taiwan, Taoyuan City, Taiwan, Zhubei City, Taiwan, Manchester, England and Neuhaus, Germany. Its wafer fabrication facility is located in Manchester, with an additional facility in Shanghai, China. Assembly and test facilities are located in Shanghai, Jinan, Chengdu, and Yangzhou, China, as well as in Hong Kong, Neuhaus and Taipei. Additional engineering, sales, warehouse, and logistics offices are located in Taipei, Hong Kong, Manchester, Shanghai, Shenzhen, China, Seongnam-si, South Korea, and Munich, Germany, with support offices throughout the world.
