Linear regulators offer 25?A quiescent supply

Maxim Integrated Products has developed small, high-input-voltage linear regulators that supply always-on, keep-alive power to CMOS RAM, real-time clocks (RTC), and microcontrollers in systems with high-voltage batteries. According to the company, the MAX8718 and MAX8719's low 25?A quiescent supply current is essential for these micropower applications.

Even when subjected to fast supply-voltage changes that occur during the switchover from battery to AC-adapter input power, the MAX8718 provides a fixed 5V or 3.3V output. On the other hand, the MAX8719 has an adjustable 1.24V to 8V output.

In addition to their principal application in notebook computers, these devices can be used in other low-power, high-voltage applications (4V < V(IN) < 28V), such as smart batteries, current-control loops, telecom emergency power, and housekeeping power for off-line supplies.

Both the MAX8718 and MAX8719 are available in a thermally enhanced, 8-pin TDFN package. These devices are screened for the -40°C to 85°C industrial temperature range. Prices start at 99 cents (1,000-up, FOB USA). A pre-assembled evaluation kit (MAX8718/MAX8719EVKIT) is available upon request.