Designing Ideas

In test-and-measurement applications, you must provide overvoltage protection for the output terminals of amplifiers, power supplies, and similar components. "Circuits protect outputs against overvoltage" disconnects the amplifier-output node from the output terminals for the period when an overload voltage exists on the output terminals.

The design of power-supply-regulation circuitry in which the primary power source has an absolute current-limit specification, such as spacecraft photovoltaic, or "solar," panels and radioisotope thermoelectric generators, demand that you control current spikes, such as those that typically occur on power-up. "Circuit limits dv/dt and capacitor inrush at regulator turn-on" shows that the best strategy for limiting the regulator's turn-on maximum current is to limit dv/dt.

When synchronizing two instruments' signals, it is important to make sure that the receiver can latch the sender's synchronous signal. You must make sure that the circuit properly calculates and generates the synchronizing signal, no matter how the user sets the output of the generator. "CPLD connects two instruments with half-duty-cycle generator" provides the program for a CPLD that divides the sender's synchronizing signal by two.

Often you need to transmit a couple of bits or bytes of data to a microcontroller without a direct cable connection. One simple way to achieve this goal is to use a widely available IR receivers that were designed for use in IR-remote-control applications, such as TVs and VCRs. "Achieve simple IR-data transmission from a PC's serial port" shows how to communicate with a microcontroller without building a complete stand-alone IR transmitter.