Circuits & Schematics - Measurement - 3

An excerpt from Christopher Paul’s “Parsing PWM (DAC) performance: Part 1 Mitigating errors” ( Ref. 1 ): “I was surprised to discover that when an output of a popular µP I’ve been using is configured to be a ...

In recent EDN design ideas, we’ve seen thermostat designs that meld the functions of sensor and heater into a single device: FET, BJT, or even a simple length of fine gauge copper wire. A virtue inherent in thermostat designs that use a ...

Let’s see how you can effectively double the output sink current of the plain old 555 timer. From the block diagram in Figure 1 taken from the datasheet of the ST’s TS555 low power single CMOS timer) we can see that the Discharge pin ...

You can use the simple sensor circuit in Figure 1 to remotely monitor the level of liquid water in a vessel such as a swimming pool. The LMC555 sensor oscillator provides an output-signal frequency that is a function of the water level. This signal ...

Pulse width modulation (PWM) is a terrific basis for digital to analog conversion. Credit goes to features like simplicity and (theoretically) perfect differential and integral linearity. Unfortunately, PWM’s need for ripple filtering tends ...

Battery stack voltage monitor development ( Reference 1 ) is aided by a floating, variable potential battery simulator. This capability permits monitor accuracy verification over a wide range of battery voltage. The floating battery simulator is ...

There are many applications where an ADC needs to process a small differential input signal in the presence of a large common-mode signal. Traditional instrumentation amplifiers (in-amps) are not commonly used in these applications, due to their ...

High speed and precision are not the only areas where special V-F circuits are needed. Figure 1 shows a circuit which runs from a single 1.5 V cell with only 125 µA current drain. The circuit uses an LT1017 dual micropower comparator in a ...

The gain temperature coefficient of conventional V-F circuits is affected by drift in the charge pumping capacitors. Although compensation schemes are employed to minimize the effect of this drift, another approach is required to get significantly ...

Manufacturers of optocouplers characterize their devices for CTR (current-transfer ratio), and an optocoupler’s data sheet will list its CTR ranges. Unfortunately, the CTR range may be too wide for some applications, requiring you to screen ...