Circuits & Schematics - 3

Digital-system designs require you to consider many core voltages. Memory operates at 1.8 V, I 2 C and FPGA devices operate at 3.3 V, microcontrollers operate at 5 V, and charge-coupled-device image sensors operate at 9 to 8 V. Clocks for each ...

A typical window comparator uses two comparators and a single op amp to determine whether a voltage is inside or outside a boundary region. Figure 1 shows a typical implementation. IC 1 is an inverting op amp with a gain of 1. V REF and V REF ...

You use high-side current monitoring in many battery-powered products that require accurate monitoring of load current, charger current, or both. In applications for nonportable designs, high-side-current monitoring serves as a power-supply ...

If you use a function generator, you may occasionally require a sine-wave output at a higher frequency than the generator can provide. If your function generator also produces a triangle-wave output, you can use a frequency doubler to extend the ...

The human eye is remarkably sensitive to changes in light level. In ambient light ranging over several orders of magnitude, the eye can detect changes of only a few percent, yielding an incredible dynamic range. The primary trick is that the ...

Most microprocessors have some type of hardware watchdog that can be used to reset the microprocessor and the surrounding hardware to a known state if firmware inadvertently stops executing code. But it may be advantageous to record the ...

An ac-based continuity tester for front-line test-and-repair jobs provides a simple go/no-go test for localizing faults in multiconductor cables (Figure 1). Open circuits are more likely to occur at the connector ends. This tool helps to identify ...

Driving multiple LEDs with one microprocessor GPIO pin is a well-known technique. Typically, designs perform this task by issuing pulse widths and clocks of differing durations and employing multiple RC networks to distinguish between them. The ...

Frequency multipliers typically work with square waves. However, the circuit in Figure 1 performs frequency multiplication on triangle waveforms and maintains the input's amplitude and uniformity. Figure 1. This circuit performs frequency ...

The design in Figure 1 is a visible optical link for those who need to see the transmitted data. An isolation figure of more than 5000 V is a bonus. Tests of the system used the COM input of a data-acquisition system, as well as a standard PC's ...