(ICs for the Electronics Bench)
This line of products is geared towards the electronics hobbyist or small business that needs a quick solution, but doesn’t have the volume to justify developing the product in house. Each integrated circuit is created with the express purpose of relieving some of the peripheral design burden for you.
We offer integrated circuits for such functions as driving piezo buzzers and LEDs, interfacing to mechanical switches, and providing stable timing signals.
Oscillators
ELM440 – 60Hz Generator
This circuit generates both 60Hz and 1Hz from a common 3.58MHz NTSC TV crystal. A synchronizing input is also provided for locking the output to a 60Hz line frequency signal if available (recommended for long-term stability). Switching between sync-lock and free-running is automatic. Handy for battery-backed clock circuits.
ELM446 – 50Hz Generator
This chip also uses a 3.58MHz NTSC television crystal to generate complementary 50Hz outputs as well as a 1Hz output. Greatly simplifies many timekeeping tasks as the 20ms period is often handier for calculations than 16.67ms. This circuit does not have a sync-lock input.
ELM460 – Impossible Oscillator
This integrated circuit uses no external timing components to generate signals with periods from 0.1 seconds to 10 minutes. Timing is digitally selected via four input pins, and complementary output signals are provided. It doesn’t have as much output drive as a 555, but sure is much easier to use.
Rotary Decoders
Our Rotary Decoder ICs make it easy to connect a rotary (quadrature) encoder to an electronic circuit. They do all the work for you, cleaning up the signal, detecting when there is jitter in the signal, and outputting logic levels that can be used directly by a variety of circuits. We currently offer several different decoder products. To help with the selection process, here is a chart that outlines some of the features of each:
While our decoders typically get used with digital potentiometers and microprocessors, they can be used virtually anywhere that you require a clean, bounce-free digital signal that represents direction.
ELM401 – Debounce Circuit
This circuit provides full debouncing for a rotary (quadrature) encoder. Two inputs use filtering as well as comparator and timing functions in order to handle the unique problem of noise due to the sliding contacts of a rotary encoder. A third input provides conventional debouncing for a pushbutton, should your encoder be equipped with one.
Depending on the application, you may want different outputs, (up, down, clock, etc.), and also may want different numbers of pulses per transition, in addition to debouncing of the signals. These circuits cover most needs:
ELM402 – 2 wire 2x Interface
The ELM402 uses the technology of the ELM401 to debounce the two quadrature signals from a rotary encoder. It then decodes these signals into an ‘up’ and a ‘down’ output. The pulse width and the polarity of the output signals can be controlled with two circuit inputs.
ELM403 – 2 wire 4x Interface
This circuit is identical to the ELM402, but it uses 4x decoding rather than 2x. This gives four output pulses when the A and B inputs go though a cycle, rather than two.
ELM404 – 3 wire 2x Interface
The ELM404 uses the technology of the ELM401 to debounce the two quadrature signals from a rotary encoder. It then decodes these signals into a ‘chip select’, a ‘clock’ and an ‘up/down’ output. The clock signal polarity can be controlled with a circuit input.
ELM405 – 3 wire 4x Interface
This circuit is identical to the ELM404, but it uses 4x decoding rather than 2x. This gives four output pulses when the A and B inputs go though a cycle, rather than two.
ELM406 – 3 wire 2x Interface
The ELM406 uses the technology of the ELM401 to debounce the two quadrature signals from a rotary encoder. It then decodes these signals into a ‘chip select’, a ‘clock’ and an ‘up/down’ output. A ‘write enable’ input can be used to change the output waveform to a pattern used by many digital potentiometers to cause a write of the wiper position to non-volatile memory.
ELM407 – 3 wire 4x Interface
This circuit is identical to the ELM406, but it uses 4x decoding rather than 2x. This gives four output pulses when the A and B inputs go though a cycle, rather than two.
ELM408 – 2 wire Interface
The ELM408 uses the technology of the ELM401 to debounce the two quadrature signals from a rotary encoder. It then decodes these signals into a ‘chip select’, and an ‘up/down’ output. Inputs are provided for ‘write enable’ (to change the output waveform to a pattern used by many digital potentiometers to cause a write of the wiper position to non-volatile memory), and for selecting either 2x or 4x decoding of the signals.
Switch Interfaces
These circuits are designed to be (typically) used between mechanical switches or relay contacts and an electronic circuit. Mechanical contacts can generate very noisy signals when the contacts meet or part, and fast electronic circuits can easily interpret this as multiple operations.
The following all process (‘debounce’) noisy input signals, and they also offer additional functionality such as latching circuits, or pulse outputs.
ELM409 – Versatile Debounce Circuit
A single debounce circuit with a wide range of settings (long and short debounce periods, pulsed or steady output, etc.)
ELM410 – Triple Debounce Circuit
Three standard 25 msec debounce circuits in one 8 pin package.
ELM411 – Debounce Circuit with Latch
Three standard 25 msec debounce circuits, one of which alternates its’ state on each press.
ELM415 – Up/Down Interface
Converts separate up/down pushbuttons to a single up/down output and count signal. Handy for providing many circuits with simple human interfaces (that would otherwise need confusing buttons).
Timers
ELM380 – Battery Charger Timer
An 8/14 hour timer that is useful for setting long periods such as battery charge cycles.
ELM381 – 60Hz Long Interval Counter
Reduce circuit board clutter when trying to obtain those very long time delays. The ELM381 provides 1 hour to 1 week periods using a 60Hz clock input. Digitally select one of four desired periods, apply a line frequency signal to the Schmitt clock input, and use the high current outputs to drive your circuit.
ELM382 – 50Hz Long Interval Timer
The ELM382 is very similar to the ELM381, except that it expects a 50Hz input for the timing signal. Outputs can be 1 hour, 12 hours, 1 day, or 1 week, exactly as the ELM381. Simply apply a line frequency signal to the Schmitt clock input, and use the high current outputs to drive your circuit.
Misc
ELM304 – NTSC Video Generator
Need an interlaced B&W TV signal? The ELM304 can provide it.
ELM412 – Piezo Element Driver
Provides adjustable frequency drive for a piezo element, without external timing elements.
ELM413 – LED Driver
Provide a delayed on control signal for your circuit while also displaying the state on a red/green LED.