San Jose, Calif.—Renesas Technology says its RNA50C27AUS is the industry's first reset IC that incorporates a core power-on sequencing function for microcontrollers that operate core logic circuits
from a 1.8-volt power supply and I/O peripheral circuits from a 3.3-volt supply.
The chip simplifies the start-up electronics by eliminating the need for the external transistor switch and timing circuit normally required for a traditional reset IC. The RNA50C27AUS monitors both supply voltages and generates a reset if either one falls below a critical level. It will detect a 1 percent error in the expected nominal outputs of the I/O supply; hysteresis is 5 percent typical. This chip also provides a control function for turning the core power supply on or off.
The device's external resistor and capacitor determine the reset signal release time. The reset output signal has fast (10 ns) rise and fall times. To accommodate the specific application, users can select an open-drain output or CMOS output from which to pick off the reset signal. Using the CMOS output allows a direct connection to a microcontroller's reset pin.
Click here for the product datasheet. Sample price for the RNA50C27AUS, in an 8-pin SSOP-8 that meets lead-free specifications, is 70 cents.
Renesas Technology, 1-408-382-7407, www.renesas.com