Dallas Semiconductor, acquired by Maxim Integrated Products in 2001, designed and manufactured analog, digital, and mixed-signal semiconductors (integrated circuits, or ics). Its specialties included communications products (including T/E and Ethernet products), microcontrollers, battery management, thermal sensing and thermal management, non-volatile random-access memory, microprocessor supervisors, delay lines, silicon oscillators, digital potentiometers, real-time clocks, temperature-compensated crystal oscillators (TCXOs), iButton, and 1-Wire products. The Dallas, Texas-based company was founded in 1984 and purchased by Maxim Integrated Products in 2001. Both the Maxim and Dallas Semiconductor brands were actively used until 2007. Since then, the Maxim name has been used for all new products, though the Dallas Semiconductor brand has been retained for some older products, which can be identified by "DS" at the beginning of their part numbers.