Circuits & Schematics Analogue Design - 4

Figure 1 is a micropower voltage-to-frequency converter. A 0 V to 5 V input produces a 0 kHz to 10 kHz output with a linearity of 0.05%. Gain drift is 80 ppm/ C. Maximum current consumption is only 90 µA, almost 30 times lower than currently ...

Analog circuits for long-term testing of passive components, such as 0.1%-tolerant resistors or high-intensity white LEDs, often require a constant current. Using two op amps and a voltage reference, you can develop a circuit that provides a ...

A typical SCR (silicon-controlled rectifier) requires a trigger current, which causes the SCR structure to latch on. Once the device latches, the current through the SCR is solely a function of external component values. The SCR has no inherent ...

The standard way of using an RTD (resistance-temperature-detector) sensor is to include it in a bridge followed by a differential amplifier. The problem is that two nonlinearities one from the sensor and another from the bridge affect the transfer ...

A resistive DAC in a resistive-feedback loop of an op amp lets you create an analog-digital-analog divider. The resistance, R WA , between the W and A terminals of the Analog Devices AD5293 (Figure 1) decreases linearly with increasing the ...

Designers often use relays as electrically controlled switches. Unlike transistors, their switch contacts are electrically isolated from the control input. However, the power dissipation in a relay coil may render the device unattractive in ...

Mechanical bounce often occurs while trying to measure current or resistance on experimental materials or from routine switch-contact action. It can be a problem if you are trying to preserve the bounce or noise phenomenon within the measurement ...

Professional electronics designers often use peak-detector circuit sin such applications as amplitude measurement, automatic gain control, and data regeneration. You can build a simple and fast peak detector from a serial diode and a shunt ...

A common problem that arises when you design lowpass filters for signal conditioning is the filters' effect on the system's time-domain response. Because pushing the cutoff frequency lower slows the step response, the system may fail to ...

This self-heated constant-temperature-delta transistor anemometer is cheap, rugged, and sensitive. It relies on the relationship between airspeed (A F ) and thermal impedance (Z T = C/W) of a heated air flow sensor as shown in the formula below for ...