Get the latest tech news
The bucket brigade device: An analog shift register
(Electronics) Nowadays, digitally delaying audio is easy, but historically we had to use devices like the TCA350, a fully analog delay line: It works by charging a small capacitor to the input voltage, and then moving that charge through a chain of hundreds more before it exists the device: The two clock signals consist of non-overlapping negative pulses, each making every other MOSFET momentarily conduct. Additionally, each pulse changes the voltage (but not charge) on every other capacitor, which helps pull charge from one stage to the next, preventing the samples from just smearing out.
There is a single MOSFET transistor in the red box, with the gate coming in from the left, and the drain and source going off the chip. Instead of discrete transistors and capacitors like the TCA350, they directly move charge trapped in inversion channel using three sets of gate wires. This requires an rather inconvenient 3 phase overlapping clock, but works amazingly well: a good CCD can move charge between a million pixels without loosing a single electron.
Or read this on Hacker News