Circuits & Schematics - 3

The original bipolar 555 timer, the NE555 , is excellent for driving a power MOSFET’s gate. Newer CMOS versions such as the 7555, LMC555, and TLC555 use less power, but they have trouble sourcing enough current to drive a gate well and can ...

A widely-used push-pull configuration of an AB class amplifier is shown in Figure 1, but it needs some improvements. Figure 1. This configuration of an AB class amplifier have some improvements. First of all, let’s take a look how its thermal ...

The LM324 is a cost-effective choice for an op amp, especially when you need to apply ground-level inputs. Although its output purportedly includes ground, its poor current-sinking capability limits the applications. At output voltages lower than ...

The circuit in Figure 1 powers a microparticle and nanoparticle ion trap through a 1-to-5-turns-ratio, high-voltage transformer. It also works successfully as a driver for a piezo-tube scanner and in a near-field scanning optical microscope. The ...

You sometimes need to drive a white LED from one 1.5 V battery. Unfortunately, the forward voltage of a white LED is 3 to 4 V. So, you would need a dc/dc converter to drive the LED from one battery. Using the simple circuit in Figure 1, you can ...

Adding a current-mirror circuit to a typical boost circuit allows you to select the amount of boost voltage and to ensure a constant difference between the input and the output voltages (Figure 1). This circuit is useful for high-side-drive ...

The growth of battery-operated applications has put steady pressure on designers to steeply reduce their products’ operational power consumption and bring standby power as close to zero as possible by carefully managing the devices’ ...

Today's digital delay lines can process pulses no shorter than their delay times, and that restriction confines the devices to applications in which the duty cycle remains near 50%. A limited range of available delays (2 to 100 nsec per tap) ...

Some applications require an input voltage higher than the breakdown voltage of the IC supply pin. In boost converters and SEPICs (single-ended primary-inductance converters), you can separate the V IN pin of the IC from the input inductor and use ...

The polarity-protection circuit in Figure 1 is a high-performance alternative to the usual series diode (often Schottky). The circuit incurs a much lower voltage drop than even the best Schottky diode. The circuit uses MOSFET devices because of ...