MIAMI, 19 July 2012. Aeroflex has released the new UT04VS33P, a radiation-hardened voltage supervisor which simultaneously monitors up to four supply levels used in a system, providing status output for each signal, VOUTx, as well as a system reset signal if any of the monitored signals moves out of range.

To set the monitor trip points, TH0 and TH1 pins allow the selection of three sets of preset threshold levels per channel, determined by an internal bandgap voltage reference, to reduce supply and temperature variance, and a fourth selection which allows the user to determine the level for each channel. There are two modes of operation determined by the OVSH pin. In the first mode, when the OVSH pin is connected to VSS, four independent supplies are monitored for an under-voltage condition. In the second mode, when the OVSH pin is connected to VDD, the under-voltage and over-voltage of the inputs are monitored. In this mode, two supplies can be monitored using channels 1 and 3 or channels 2 and 4, respectively. For flexibility, both system RESET and RESETB outputs are available for interfacing to the system. Each channel has an enable, ENx, allowing use of one, two, three or all four monitor channels.

The margin (or tolerance) to the given threshold voltage for under-voltage monitoring is determined by the setting of the TOL pin. The logic sense of the channel 3 and 4 outputs can be inverted by setting the INV pin appropriately. Also MRB, the master reset, provides a means for a manual input to activate the RESET signals. In addition, the user can adjust two timing parameters by the addition of external capacitors to the device. These are the response times of the channel VOUTx signal when the associated input returns to a valid level, implemented by CDLYx, and the time to clear RESET (and RESETB) when a channel enable or input level becomes valid; implemented by CRESET.

The UT04VS33P supervisory circuit reduces the complexity and number of circuits required to monitor power supply and battery functions in microprocessor, DSP, microcontroller, ASIC and FPGA systems. The UT04VS33P supervisory circuit helps improves system reliability and accuracy in the systems it is included in.