Circuits & Schematics

Often you want to turn on and off power to a device with a single pushbutton switch. The circuit below performs this logic function with just a few parts and can operate from DC supplies between +3 V to about 15 V. It uses two inverters within a ...

I designed the circuit in Figure 1 as a part of a data transmission system that has a carrier frequency of 400 kHz using on-off keying (OOK) modulation. Figure 1. A digital frequency divider circuit that detects the presence of a 400-kHz carrier, ...

Up front: some background. The air-temperature sensor attached to my (home-brew) rain gauge became flaky. Short-term solution: fix it (done). Longer-term goal: improve it (read on). That sensor is a standard Vishay NTC (negative temperature ...

Two inexpensive ICs divide a TTL clock signal by 1.5. By following the circuit with another flip/flop, you could also generate a divide by three function. Materials on the topic Datasheet Texas Instruments SN74HCT02 Datasheet Texas Instruments ...

A common problem for power-supply designers is to create a compact, dual-polarity step-down converter. If space and cost are not concerns, the obvious solution is a pair of DC/DC converters, one for each output. But space and cost are almost always ...

Most electronic clocks, be they analog or digital, use a crystal oscillator (XO) based on a 32.768 kHz crystal for their reference. In fact, it is same crystal that’s commonly used as a real-time clock for many microcontroller systems. These ...

Simple linear and switching voltage regulators with feedback networks of the type shown in Figure 1 are legion. Their output voltages are the reference voltage at the feedback (FB) pin multiplied by 1 + R F /R G . Recommended values of C F from 100 ...

Many applications use FPGAs, ASICs, or DSP chips, which usually require multiple voltage rails, typically two: the core voltage and the I/O voltage. The core voltage is usually lower than the I/O voltage. Guidelines for determining how to power up ...

A simple module to keep power banks from turning off, when your DIY circuit draws low currents. A simple power bank keep alive module. As the name is already suggesting, this module keeps power banks from auto turn off, when the load current is too ...

A while back, I published the Design Idea (DI) “Simple PWM interface can program regulators for V OUT V SENSE ” ( Ref. 1 )It showed some simple circuits for PWM programming of standard bucking-type regulator chips, both linear and ...